/*
* Copyright 2011-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://aws.amazon.com/apache2.0
*
* This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES
* OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and
* limitations under the License.
*/
package com.amazonaws.mobileconnectors.dynamodbv2.dynamodbmapper;
import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.AmazonWebServiceRequest;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.mobileconnectors.dynamodbv2.dynamodbmapper.DynamoDBMapperConfig.ConsistentReads;
import com.amazonaws.mobileconnectors.dynamodbv2.dynamodbmapper.DynamoDBMapperConfig.PaginationLoadingStrategy;
import com.amazonaws.mobileconnectors.dynamodbv2.dynamodbmapper.DynamoDBMapperConfig.SaveBehavior;
import com.amazonaws.mobileconnectors.dynamodbv2.dynamodbmapper.DynamoDBTableSchemaParser.TableIndexesInfo;
import com.amazonaws.retry.RetryUtils;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.model.AttributeAction;
import com.amazonaws.services.dynamodbv2.model.AttributeValue;
import com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate;
import com.amazonaws.services.dynamodbv2.model.BatchGetItemRequest;
import com.amazonaws.services.dynamodbv2.model.BatchGetItemResult;
import com.amazonaws.services.dynamodbv2.model.BatchWriteItemRequest;
import com.amazonaws.services.dynamodbv2.model.BatchWriteItemResult;
import com.amazonaws.services.dynamodbv2.model.ComparisonOperator;
import com.amazonaws.services.dynamodbv2.model.Condition;
import com.amazonaws.services.dynamodbv2.model.ConditionalCheckFailedException;
import com.amazonaws.services.dynamodbv2.model.ConditionalOperator;
import com.amazonaws.services.dynamodbv2.model.CreateTableRequest;
import com.amazonaws.services.dynamodbv2.model.DeleteItemRequest;
import com.amazonaws.services.dynamodbv2.model.DeleteRequest;
import com.amazonaws.services.dynamodbv2.model.ExpectedAttributeValue;
import com.amazonaws.services.dynamodbv2.model.GetItemRequest;
import com.amazonaws.services.dynamodbv2.model.GetItemResult;
import com.amazonaws.services.dynamodbv2.model.KeysAndAttributes;
import com.amazonaws.services.dynamodbv2.model.PutItemRequest;
import com.amazonaws.services.dynamodbv2.model.PutItemResult;
import com.amazonaws.services.dynamodbv2.model.PutRequest;
import com.amazonaws.services.dynamodbv2.model.QueryRequest;
import com.amazonaws.services.dynamodbv2.model.QueryResult;
import com.amazonaws.services.dynamodbv2.model.ReturnValue;
import com.amazonaws.services.dynamodbv2.model.ScanRequest;
import com.amazonaws.services.dynamodbv2.model.ScanResult;
import com.amazonaws.services.dynamodbv2.model.Select;
import com.amazonaws.services.dynamodbv2.model.UpdateItemRequest;
import com.amazonaws.services.dynamodbv2.model.UpdateItemResult;
import com.amazonaws.services.dynamodbv2.model.WriteRequest;
import com.amazonaws.services.s3.model.Region;
import com.amazonaws.util.VersionInfoUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;
import java.util.Set;
import java.util.UUID;
/**
* Object mapper for domain-object interaction with DynamoDB.
* <p>
* To use, define a domain class that represents an item in a DynamoDB table and
* annotate it with the annotations found in the
* com.amazonaws.mobileconnectors.dynamodbv2.dynamodbmapper package. In order to
* allow the mapper to correctly persist the data, each modeled property in the
* domain class should be accessible via getter and setter methods, and each
* property annotation should be either applied to the getter method or the
* class field. A minimal example using getter annotations:
*
* <pre class="brush: java">
* @DynamoDBTable(tableName = "TestTable")
* public class TestClass {
*
* private Long key;
* private double rangeKey;
* private Long version;
*
* private Set<Integer> integerSetAttribute;
*
* @DynamoDBHashKey
* public Long getKey() {
* return key;
* }
*
* public void setKey(Long key) {
* this.key = key;
* }
*
* @DynamoDBRangeKey
* public double getRangeKey() {
* return rangeKey;
* }
*
* public void setRangeKey(double rangeKey) {
* this.rangeKey = rangeKey;
* }
*
* @DynamoDBAttribute(attributeName = "integerSetAttribute")
* public Set<Integer> getIntegerAttribute() {
* return integerSetAttribute;
* }
*
* public void setIntegerAttribute(Set<Integer> integerAttribute) {
* this.integerSetAttribute = integerAttribute;
* }
*
* @DynamoDBVersionAttribute
* public Long getVersion() {
* return version;
* }
*
* public void setVersion(Long version) {
* this.version = version;
* }
* }
* </pre>
* <p>
* Save instances of annotated classes to DynamoDB, retrieve them, and delete
* them using the {@link DynamoDBMapper} class, as in the following example.
*
* <pre class="brush: java">
* DynamoDBMapper mapper = new DynamoDBMapper(dynamoDBClient);
* Long hashKey = 105L;
* double rangeKey = 1.0d;
* TestClass obj = mapper.load(TestClass.class, hashKey, rangeKey);
* obj.getIntegerAttribute().add(42);
* mapper.save(obj);
* mapper.delete(obj);
* </pre>
* <p>
* When using the save, load, and delete methods, {@link DynamoDBMapper} will
* throw {@link DynamoDBMappingException}s to indicate that domain classes are
* incorrectly annotated or otherwise incompatible with this class. Service
* exceptions will always be propagated as {@link AmazonClientException}, and
* DynamoDB-specific subclasses such as {@link ConditionalCheckFailedException}
* will be used when possible.
* <p>
* This class is thread-safe and can be shared between threads. It's also very
* lightweight, so it doesn't need to be.
*
* @see DynamoDBTable
* @see DynamoDBHashKey
* @see DynamoDBRangeKey
* @see DynamoDBAutoGeneratedKey
* @see DynamoDBAttribute
* @see DynamoDBVersionAttribute
* @see DynamoDBIgnore
* @see DynamoDBMarshalling
* @see DynamoDBMapperConfig
*/
public class DynamoDBMapper {
private final S3ClientCache s3cc;
private final AmazonDynamoDB db;
private final DynamoDBMapperConfig config;
private final DynamoDBReflector reflector = new DynamoDBReflector();
private final DynamoDBTableSchemaParser schemaParser = new DynamoDBTableSchemaParser();
private final VersionIncrementor incrementor = new VersionIncrementor();
private final AttributeTransformer transformer;
/** The max back off time for batch write */
static final long MAX_BACKOFF_IN_MILLISECONDS = 1000 * 3;
/** The max number of items allowed in a BatchWrite request */
static final int MAX_ITEMS_PER_BATCH = 25;
/**
* This retry count is applicable only when every batch get item request
* results in no data retrieved from server and the un processed keys is
* same as request items
*/
static final int BATCH_GET_MAX_RETRY_COUNT_ALL_KEYS = 5;
/**
* User agent for requests made using the {@link DynamoDBMapper}.
*/
private static final String USER_AGENT =
DynamoDBMapper.class.getName() + "/" + VersionInfoUtils.getVersion();
private static final String USER_AGENT_BATCH_OPERATION =
DynamoDBMapper.class.getName() + "_batch_operation/" + VersionInfoUtils.getVersion();
private static final String NO_RANGE_KEY = new String();
private static final Log log = LogFactory.getLog(DynamoDBMapper.class);
/**
* Constructs a new mapper with the service object given, using the default
* configuration.
*
* @param dynamoDB The service object to use for all service calls.
* @see DynamoDBMapperConfig#DEFAULT
*/
public DynamoDBMapper(final AmazonDynamoDB dynamoDB) {
this(dynamoDB, DynamoDBMapperConfig.DEFAULT, null, null);
}
/**
* Constructs a new mapper with the service object and configuration given.
*
* @param dynamoDB The service object to use for all service calls.
* @param config The default configuration to use for all service calls. It
* can be overridden on a per-operation basis.
*/
public DynamoDBMapper(
final AmazonDynamoDB dynamoDB,
final DynamoDBMapperConfig config) {
this(dynamoDB, config, null, null);
}
/**
* Constructs a new mapper with the service object and S3 client cache
* given, using the default configuration.
*
* @param ddb The service object to use for all service calls.
* @param s3CredentialProvider The credentials provider for accessing S3.
* Relevant only if {@link S3Link} is involved.
* @see DynamoDBMapperConfig#DEFAULT
*/
public DynamoDBMapper(
final AmazonDynamoDB ddb,
final AWSCredentialsProvider s3CredentialProvider) {
this(ddb, DynamoDBMapperConfig.DEFAULT, s3CredentialProvider);
}
/**
* Constructs a new mapper with the given service object, configuration, and
* transform hook.
*
* @param dynamoDB the service object to use for all service calls
* @param config the default configuration to use for all service calls. It
* can be overridden on a per-operation basis
* @param transformer The custom attribute transformer to invoke when
* serializing or deserializing an object.
*/
public DynamoDBMapper(
final AmazonDynamoDB dynamoDB,
final DynamoDBMapperConfig config,
final AttributeTransformer transformer) {
this(dynamoDB, config, transformer, null);
}
/**
* Constructs a new mapper with the service object, configuration, and S3
* client cache given.
*
* @param dynamoDB The service object to use for all service calls.
* @param config The default configuration to use for all service calls. It
* can be overridden on a per-operation basis.
* @param s3CredentialProvider The credentials provider for accessing S3.
* Relevant only if {@link S3Link} is involved.
*/
public DynamoDBMapper(
final AmazonDynamoDB dynamoDB,
final DynamoDBMapperConfig config,
final AWSCredentialsProvider s3CredentialProvider) {
this(dynamoDB, config, null, validate(s3CredentialProvider));
}
/**
* Throws an exception if the given credentials provider is {@code null}.
*/
private static AWSCredentialsProvider validate(
final AWSCredentialsProvider provider) {
if (provider == null) {
throw new IllegalArgumentException(
"s3 credentials provider must not be null");
}
return provider;
}
/**
* Constructor with all parameters.
*
* @param dynamoDB The service object to use for all service calls.
* @param config The default configuration to use for all service calls. It
* can be overridden on a per-operation basis.
* @param transformer The custom attribute transformer to invoke when
* serializing or deserializing an object.
* @param s3CredentialProvider The credentials provider for accessing S3.
* Relevant only if {@link S3Link} is involved.
*/
public DynamoDBMapper(
final AmazonDynamoDB dynamoDB,
final DynamoDBMapperConfig config,
final AttributeTransformer transformer,
final AWSCredentialsProvider s3CredentialsProvider) {
this.db = dynamoDB;
this.config = config;
this.transformer = transformer;
if (s3CredentialsProvider == null) {
this.s3cc = null;
} else {
this.s3cc = new S3ClientCache(s3CredentialsProvider.getCredentials());
}
}
/**
* Loads an object with the hash key given and a configuration override.
* This configuration overrides the default provided at object construction.
*
* @see DynamoDBMapper#load(Class, Object, Object, DynamoDBMapperConfig)
*/
public <T extends Object> T load(Class<T> clazz, Object hashKey, DynamoDBMapperConfig config) {
return load(clazz, hashKey, null, config);
}
/**
* Loads an object with the hash key given, using the default configuration.
*
* @see DynamoDBMapper#load(Class, Object, Object, DynamoDBMapperConfig)
*/
public <T extends Object> T load(Class<T> clazz, Object hashKey) {
return load(clazz, hashKey, null, config);
}
/**
* Loads an object with a hash and range key, using the default
* configuration.
*
* @see DynamoDBMapper#load(Class, Object, Object, DynamoDBMapperConfig)
*/
public <T extends Object> T load(Class<T> clazz, Object hashKey, Object rangeKey) {
return load(clazz, hashKey, rangeKey, config);
}
/**
* Returns an object whose keys match those of the prototype key object
* given, or null if no such item exists.
*
* @param keyObject An object of the class to load with the keys values to
* match.
* @see DynamoDBMapper#load(Object, DynamoDBMapperConfig)
*/
public <T extends Object> T load(T keyObject) {
return load(keyObject, this.config);
}
/**
* Returns an object whose keys match those of the prototype key object
* given, or null if no such item exists.
*
* @param keyObject An object of the class to load with the keys values to
* match.
* @param config Configuration for the service call to retrieve the object
* from DynamoDB. This configuration overrides the default given
* at construction.
*/
public <T extends Object> T load(T keyObject, DynamoDBMapperConfig config) {
@SuppressWarnings("unchecked")
Class<T> clazz = (Class<T>) keyObject.getClass();
config = mergeConfig(config);
ItemConverter converter = getConverter(config);
String tableName = getTableName(clazz, keyObject, config);
GetItemRequest rq = new GetItemRequest()
.withRequestMetricCollector(config.getRequestMetricCollector());
Map<String, AttributeValue> key = getKey(converter, keyObject, clazz);
rq.setKey(key);
rq.setTableName(tableName);
rq.setConsistentRead(config.getConsistentReads() == ConsistentReads.CONSISTENT);
GetItemResult item = db.getItem(applyUserAgent(rq));
Map<String, AttributeValue> itemAttributes = item.getItem();
if (itemAttributes == null) {
return null;
}
T object = privateMarshallIntoObject(
converter,
toParameters(itemAttributes, clazz, tableName, config));
return object;
}
/**
* Returns a key map for the key object given.
*
* @param keyObject The key object, corresponding to an item in a dynamo
* table.
*/
@SuppressWarnings("unchecked")
private <T> Map<String, AttributeValue> getKey(
ItemConverter converter,
T keyObject) {
return getKey(converter, keyObject, (Class<T>) keyObject.getClass());
}
private <T> Map<String, AttributeValue> getKey(
ItemConverter converter,
T keyObject,
Class<T> clazz) {
Map<String, AttributeValue> key = new HashMap<String, AttributeValue>();
for (Method keyGetter : reflector.getPrimaryKeyGetters(clazz)) {
Object getterResult =
ReflectionUtils.safeInvoke(keyGetter, keyObject);
AttributeValue keyAttributeValue =
converter.convert(keyGetter, getterResult);
if (keyAttributeValue == null) {
throw new DynamoDBMappingException(
"Null key found for " + keyGetter);
}
key.put(reflector.getAttributeName(keyGetter), keyAttributeValue);
}
if (key.isEmpty()) {
throw new DynamoDBMappingException(
"Class must be annotated with " + DynamoDBHashKey.class
+ " and " + DynamoDBRangeKey.class);
}
return key;
}
/**
* Returns an object with the given hash key, or null if no such object
* exists.
*
* @param clazz The class to load, corresponding to a DynamoDB table.
* @param hashKey The key of the object.
* @param rangeKey The range key of the object, or null for tables without a
* range key.
* @param config Configuration for the service call to retrieve the object
* from DynamoDB. This configuration overrides the default given
* at construction.
*/
public <T extends Object> T load(Class<T> clazz, Object hashKey, Object rangeKey,
DynamoDBMapperConfig config) {
config = mergeConfig(config);
T keyObject = createKeyObject(clazz, hashKey, rangeKey);
return load(keyObject, config);
}
/**
* Creates a key prototype object for the class given with the single hash
* and range key given.
*/
<T> T createKeyObject(Class<T> clazz, Object hashKey, Object rangeKey) {
T keyObject = null;
try {
keyObject = clazz.newInstance();
} catch (Exception e) {
throw new DynamoDBMappingException("Failed to instantiate class", e);
}
boolean seenHashKey = false;
boolean seenRangeKey = false;
for (Method getter : reflector.getPrimaryKeyGetters(clazz)) {
if (ReflectionUtils.getterOrFieldHasAnnotation(getter, DynamoDBHashKey.class)) {
if (seenHashKey) {
throw new DynamoDBMappingException(
"Found more than one method annotated with "
+ DynamoDBHashKey.class
+ " for class "
+ clazz
+ ". Use load(Object) for tables with more than a single hash and range key.");
}
seenHashKey = true;
ReflectionUtils.safeInvoke(reflector.getSetter(getter), keyObject, hashKey);
} else if (ReflectionUtils.getterOrFieldHasAnnotation(getter, DynamoDBRangeKey.class)) {
if (seenRangeKey) {
throw new DynamoDBMappingException(
"Found more than one method annotated with "
+ DynamoDBRangeKey.class
+ " for class "
+ clazz
+ ". Use load(Object) for tables with more than a single hash and range key.");
}
seenRangeKey = true;
ReflectionUtils.safeInvoke(reflector.getSetter(getter), keyObject, rangeKey);
}
}
if (!seenHashKey) {
throw new DynamoDBMappingException("No method annotated with " + DynamoDBHashKey.class
+ " for class "
+ clazz + ".");
} else if (rangeKey != null && !seenRangeKey) {
throw new DynamoDBMappingException("No method annotated with " + DynamoDBRangeKey.class
+ " for class "
+ clazz + ".");
}
return keyObject;
}
/**
* Returns a map of attribute name to EQ condition for the key prototype
* object given. This method considers attributes annotated with either
* {@link DynamoDBHashKey} or {@link DynamoDBIndexHashKey}.
*
* @param obj The prototype object that includes the hash key value.
* @return A map of hash key attribute name to EQ condition for the key
* prototype object, or an empty map if obj is null.
*/
private Map<String, Condition> getHashKeyEqualsConditions(
ItemConverter converter,
Object obj) {
Map<String, Condition> conditions = new HashMap<String, Condition>();
if (obj == null) {
return conditions;
}
for (Method getter : reflector.getRelevantGetters(obj.getClass())) {
if (ReflectionUtils.getterOrFieldHasAnnotation(
getter, DynamoDBHashKey.class)
|| ReflectionUtils.getterOrFieldHasAnnotation(
getter, DynamoDBIndexHashKey.class)) {
Object getterReturnResult =
ReflectionUtils.safeInvoke(getter, obj);
if (getterReturnResult != null) {
conditions.put(
reflector.getAttributeName(getter),
new Condition()
.withComparisonOperator(ComparisonOperator.EQ)
.withAttributeValueList(
converter.convert(getter, getterReturnResult)));
}
}
}
return conditions;
}
/**
* Returns the table name for the class given.
*/
protected final String getTableName(final Class<?> clazz,
final DynamoDBMapperConfig config) {
return internalGetTableName(clazz, null, config);
}
/**
* Returns the table name for the class or object given.
*/
protected final String getTableName(final Class<?> clazz,
final Object object,
final DynamoDBMapperConfig config) {
return internalGetTableName(clazz, object, config);
}
static String internalGetTableName(final Class<?> clazz,
final Object object,
final DynamoDBMapperConfig config) {
// Resolve by object, if possible and desired
DynamoDBMapperConfig.ObjectTableNameResolver objectResolver = config
.getObjectTableNameResolver();
if (object != null && objectResolver != null) {
return objectResolver.getTableName(object, config);
}
// Resolve by class
DynamoDBMapperConfig.TableNameResolver classResolver = config.getTableNameResolver();
if (classResolver == null) {
classResolver = DynamoDBMapperConfig.DefaultTableNameResolver.INSTANCE;
}
return classResolver.getTableName(clazz, config);
}
/**
* Creates and fills in the attributes on an instance of the class given
* with the attributes given.
* <p>
* This is accomplished by looking for getter methods annotated with an
* appropriate annotation, then looking for matching attribute names in the
* item attribute map.
* <p>
* This method is no longer called by load/scan/query methods. If you are
* overriding this method, please switch to using an AttributeTransformer
*
* @param clazz The class to instantiate and hydrate
* @param itemAttributes The set of item attributes, keyed by attribute
* name.
*/
public <T> T marshallIntoObject(
Class<T> clazz,
Map<String, AttributeValue> itemAttributes) {
ItemConverter converter = getConverter(config);
String tableName = getTableName(clazz, config);
return privateMarshallIntoObject(
converter,
toParameters(itemAttributes, clazz, tableName, config));
}
/**
* The one true implementation of marshallIntoObject.
*/
private <T> T privateMarshallIntoObject(
ItemConverter converter,
AttributeTransformer.Parameters<T> parameters) {
Class<T> clazz = parameters.getModelClass();
Map<String, AttributeValue> values = untransformAttributes(parameters);
return converter.unconvert(clazz, values);
}
/**
* Unmarshalls the list of item attributes into objects of type clazz.
* <p>
* This method is no longer called by load/scan/query methods. If you are
* overriding this method, please switch to using an AttributeTransformer
*
* @see DynamoDBMapper#marshallIntoObject(Class, Map)
*/
public <T> List<T> marshallIntoObjects(Class<T> clazz,
List<Map<String, AttributeValue>> itemAttributes) {
List<T> result = new ArrayList<T>(itemAttributes.size());
for (Map<String, AttributeValue> item : itemAttributes) {
result.add(marshallIntoObject(clazz, item));
}
return result;
}
/**
* A replacement for {@link #marshallIntoObjects(Class, List)} that takes an
* extra set of parameters to be tunneled through to
* {@code privateMarshalIntoObject} (if nothing along the way is
* overridden). It's package-private because some of the Paginated*List
* classes call back into it, but final because no one, even in this
* package, should ever override it.
*/
final <T> List<T> marshallIntoObjects(
final List<AttributeTransformer.Parameters<T>> parameters
) {
List<T> result = new ArrayList<T>(parameters.size());
ItemConverter converter = null;
if (!parameters.isEmpty()) {
converter = getConverter(parameters.get(0).getMapperConfig());
}
for (AttributeTransformer.Parameters<T> entry : parameters) {
result.add(privateMarshallIntoObject(converter, entry));
}
return result;
}
/**
* Saves the object given into DynamoDB, using the default configuration.
*
* @see DynamoDBMapper#save(Object, DynamoDBSaveExpression,
* DynamoDBMapperConfig)
*/
public <T extends Object> void save(T object) {
save(object, null, config);
}
/**
* Saves the object given into DynamoDB, using the default configuration and
* the specified saveExpression.
*
* @see DynamoDBMapper#save(Object, DynamoDBSaveExpression,
* DynamoDBMapperConfig)
*/
public <T extends Object> void save(T object, DynamoDBSaveExpression saveExpression) {
save(object, saveExpression, config);
}
boolean needAutoGenerateAssignableKey(Class<?> clazz, Object object) {
Collection<Method> keyGetters = reflector.getPrimaryKeyGetters(clazz);
boolean forcePut = false;
/*
* Determine if there are any auto-assigned keys to assign. If so, force
* a put and assign the keys.
*/
boolean hashKeyGetterFound = false;
for (Method method : keyGetters) {
Object getterResult = ReflectionUtils.safeInvoke(method, object);
if (getterResult == null && reflector.isAssignableKey(method)) {
forcePut = true;
}
if (ReflectionUtils.getterOrFieldHasAnnotation(method, DynamoDBHashKey.class)) {
hashKeyGetterFound = true;
}
}
if (!hashKeyGetterFound) {
throw new DynamoDBMappingException("No " + DynamoDBHashKey.class
+ " annotation found in class " + clazz);
}
return forcePut;
}
/**
* Saves the object given into DynamoDB, using the specified configuration.
*
* @see DynamoDBMapper#save(Object, DynamoDBSaveExpression,
* DynamoDBMapperConfig)
*/
public <T extends Object> void save(T object, DynamoDBMapperConfig config) {
save(object, null, config);
}
/**
* Saves an item in DynamoDB. The service method used is determined by the
* {@link DynamoDBMapperConfig#getSaveBehavior()} value, to use either
* {@link AmazonDynamoDB#putItem(PutItemRequest)} or
* {@link AmazonDynamoDB#updateItem(UpdateItemRequest)}:
* <ul>
* <li><b>UPDATE</b> (default) : UPDATE will not affect unmodeled attributes
* on a save operation and a null value for the modeled attribute will
* remove it from that item in DynamoDB. Because of the limitation of
* updateItem request, the implementation of UPDATE will send a putItem
* request when a key-only object is being saved, and it will send another
* updateItem request if the given key(s) already exists in the table.</li>
* <li><b>UPDATE_SKIP_NULL_ATTRIBUTES</b> : Similar to UPDATE except that it
* ignores any null value attribute(s) and will NOT remove them from that
* item in DynamoDB. It also guarantees to send only one single updateItem
* request, no matter the object is key-only or not.</li>
* <li><b>CLOBBER</b> : CLOBBER will clear and replace all attributes,
* included unmodeled ones, (delete and recreate) on save. Versioned field
* constraints will also be disregarded.</li>
* </ul>
* Any options specified in the saveExpression parameter will be overlaid on
* any constraints due to versioned attributes.
*
* @param object The object to save into DynamoDB
* @param saveExpression The options to apply to this save request
* @param config The configuration to use, which overrides the default
* provided at object construction.
* @see DynamoDBMapperConfig.SaveBehavior
*/
public <T extends Object> void save(T object, DynamoDBSaveExpression saveExpression,
final DynamoDBMapperConfig config) {
final DynamoDBMapperConfig finalConfig = mergeConfig(config);
final ItemConverter converter = getConverter(finalConfig);
@SuppressWarnings("unchecked")
Class<? extends T> clazz = (Class<? extends T>) object.getClass();
String tableName = getTableName(clazz, object, finalConfig);
/*
* We force a putItem request instead of updateItem request either when
* CLOBBER is configured, or part of the primary key of the object needs
* to be auto-generated.
*/
boolean forcePut = (finalConfig.getSaveBehavior() == SaveBehavior.CLOBBER)
|| needAutoGenerateAssignableKey(clazz, object);
SaveObjectHandler saveObjectHandler;
if (forcePut) {
saveObjectHandler = this.new SaveObjectHandler(clazz, object,
tableName, finalConfig, converter, saveExpression) {
@Override
protected void onKeyAttributeValue(String attributeName,
AttributeValue keyAttributeValue) {
/* Treat key values as common attribute value updates. */
getAttributeValueUpdates().put(attributeName,
new AttributeValueUpdate().withValue(keyAttributeValue)
.withAction("PUT"));
}
/* Use default implementation of onNonKeyAttribute(...) */
@Override
protected void onNullNonKeyAttribute(String attributeName) {
/*
* When doing a force put, we can safely ignore the
* null-valued attributes.
*/
return;
}
@Override
protected void executeLowLevelRequest() {
/* Send a putItem request */
doPutItem();
}
};
} else {
saveObjectHandler = this.new SaveObjectHandler(clazz, object,
tableName, finalConfig, converter, saveExpression) {
@Override
protected void onKeyAttributeValue(String attributeName,
AttributeValue keyAttributeValue) {
/*
* Put it in the key collection which is later used in the
* updateItem request.
*/
getKeyAttributeValues().put(attributeName, keyAttributeValue);
}
@Override
protected void onNonKeyAttribute(String attributeName,
AttributeValue currentValue) {
/*
* If it's a set attribute and the mapper is configured with
* APPEND_SET, we do an "ADD" update instead of the default
* "PUT".
*/
if (getLocalSaveBehavior() == SaveBehavior.APPEND_SET) {
if (currentValue.getBS() != null
|| currentValue.getNS() != null
|| currentValue.getSS() != null) {
getAttributeValueUpdates().put(
attributeName,
new AttributeValueUpdate().withValue(
currentValue).withAction("ADD"));
return;
}
}
/* Otherwise, we do the default "PUT" update. */
super.onNonKeyAttribute(attributeName, currentValue);
}
@Override
protected void onNullNonKeyAttribute(String attributeName) {
/*
* If UPDATE_SKIP_NULL_ATTRIBUTES or APPEND_SET is
* configured, we don't delete null value attributes.
*/
if (getLocalSaveBehavior() == SaveBehavior.UPDATE_SKIP_NULL_ATTRIBUTES
|| getLocalSaveBehavior() == SaveBehavior.APPEND_SET) {
return;
}
else {
/* Delete attributes that are set as null in the object. */
getAttributeValueUpdates()
.put(attributeName,
new AttributeValueUpdate()
.withAction("DELETE"));
}
}
@Override
protected void executeLowLevelRequest() {
UpdateItemResult updateItemResult = doUpdateItem();
// The UpdateItem request is specified to return ALL_NEW
// attributes of the affected item. So if the returned
// UpdateItemResult does not include any ReturnedAttributes,
// it indicates the UpdateItem failed silently (e.g. the
// key-only-put nightmare -
// https://forums.aws.amazon.com/thread.jspa?threadID=86798&tstart=25),
// in which case we should re-send a PutItem
// request instead.
if (updateItemResult.getAttributes() == null
|| updateItemResult.getAttributes().isEmpty()) {
// Before we proceed with PutItem, we need to put all
// the key attributes (prepared for the
// UpdateItemRequest) into the AttributeValueUpdates
// collection.
for (String keyAttributeName : getKeyAttributeValues().keySet()) {
getAttributeValueUpdates().put(
keyAttributeName,
new AttributeValueUpdate()
.withValue(
getKeyAttributeValues().get(keyAttributeName))
.withAction("PUT"));
}
doPutItem();
}
}
};
}
saveObjectHandler.execute();
}
/**
* The handler for saving object using DynamoDBMapper. Caller should
* implement the abstract methods to provide the expected behavior on each
* scenario, and this handler will take care of all the other basic workflow
* and common operations.
*/
protected abstract class SaveObjectHandler {
protected final Object object;
protected final Class<?> clazz;
private final String tableName;
private final DynamoDBMapperConfig saveConfig;
private final ItemConverter converter;
private final Map<String, AttributeValue> key;
private final Map<String, AttributeValueUpdate> updateValues;
/**
* Any expected value conditions specified by the implementation of
* DynamoDBMapper, e.g. value assertions on versioned attributes.
*/
private final Map<String, ExpectedAttributeValue> internalExpectedValueAssertions;
/**
* Additional expected value conditions specified by the user.
*/
protected final Map<String, ExpectedAttributeValue> userProvidedExpectedValueConditions;
/**
* Condition operator on the additional expected value conditions
* specified by the user.
*/
protected final String userProvidedConditionOperator;
private final List<ValueUpdate> inMemoryUpdates;
/**
* Constructs a handler for saving the specified model object.
*
* @param object The model object to be saved.
* @param clazz The domain class of the object.
* @param tableName The table name.
* @param saveConifg The mapper configuration used for this save.
* @param saveExpression The save expression, including the
* user-provided conditions and an optional logic operator.
*/
public SaveObjectHandler(
Class<?> clazz,
Object object,
String tableName,
DynamoDBMapperConfig saveConfig,
ItemConverter converter,
DynamoDBSaveExpression saveExpression) {
this.clazz = clazz;
this.object = object;
this.tableName = tableName;
this.saveConfig = saveConfig;
this.converter = converter;
if (saveExpression != null) {
userProvidedExpectedValueConditions = saveExpression
.getExpected();
userProvidedConditionOperator = saveExpression
.getConditionalOperator();
} else {
userProvidedExpectedValueConditions = null;
userProvidedConditionOperator = null;
}
updateValues = new HashMap<String, AttributeValueUpdate>();
internalExpectedValueAssertions = new HashMap<String, ExpectedAttributeValue>();
inMemoryUpdates = new LinkedList<ValueUpdate>();
key = new HashMap<String, AttributeValue>();
}
/**
* The general workflow of a save operation.
*/
public void execute() {
Collection<Method> keyGetters = reflector.getPrimaryKeyGetters(clazz);
/*
* First handle keys
*/
for (Method method : keyGetters) {
Object getterResult = ReflectionUtils.safeInvoke(method, object);
String attributeName = reflector.getAttributeName(method);
if (getterResult == null && reflector.isAssignableKey(method)) {
onAutoGenerateAssignableKey(method, attributeName);
}
else {
AttributeValue newAttributeValue = converter.convert(method, getterResult);
if (newAttributeValue == null) {
throw new DynamoDBMappingException(
"Null or empty value for key: " + method);
}
if (newAttributeValue.getS() == null
&& newAttributeValue.getN() == null
&& newAttributeValue.getB() == null) {
throw new DynamoDBMappingException(
"Keys must be scalar values (String, Number, "
+ "or Binary). Got " + newAttributeValue
+ " for key " + method);
}
onKeyAttributeValue(attributeName, newAttributeValue);
}
}
/*
* Next construct an update for every non-key property
*/
for (Method method : reflector.getRelevantGetters(clazz)) {
// Skip any key methods, since they are handled separately
if (keyGetters.contains(method))
continue;
Object getterResult = ReflectionUtils.safeInvoke(method, object);
String attributeName = reflector.getAttributeName(method);
/*
* If this is a versioned field, update it
*/
if (reflector.isVersionAttributeGetter(method)) {
onVersionAttribute(method, getterResult, attributeName);
}
/*
* Otherwise apply the update value for this attribute.
*/
else {
AttributeValue currentValue = converter.convert(method, getterResult);
if (currentValue != null) {
onNonKeyAttribute(attributeName, currentValue);
} else {
onNullNonKeyAttribute(attributeName);
}
}
}
/*
* Execute the implementation of the low level request.
*/
executeLowLevelRequest();
/*
* Finally, after the service call has succeeded, update the
* in-memory object with new field values as appropriate. This
* currently takes into account of auto-generated keys and versioned
* attributes.
*/
for (ValueUpdate update : inMemoryUpdates) {
update.apply();
}
}
/**
* Implement this method to do the necessary operations when a key
* attribute is set with some value.
*
* @param attributeName The name of the key attribute.
* @param keyAttributeValue The AttributeValue of the key attribute as
* specified in the object.
*/
protected abstract void onKeyAttributeValue(String attributeName,
AttributeValue keyAttributeValue);
/**
* Implement this method for necessary operations when a non-key
* attribute is set a non-null value in the object. The default
* implementation simply adds a "PUT" update for the given attribute.
*
* @param attributeName The name of the non-key attribute.
* @param currentValue The updated value of the given attribute.
*/
protected void onNonKeyAttribute(String attributeName, AttributeValue currentValue) {
updateValues.put(attributeName, new AttributeValueUpdate()
.withValue(currentValue).withAction("PUT"));
}
/**
* Implement this method for necessary operations when a non-key
* attribute is set null in the object.
*
* @param attributeName The name of the non-key attribute.
*/
protected abstract void onNullNonKeyAttribute(String attributeName);
/**
* Implement this method to send the low-level request that is necessary
* to complete the save operation.
*/
protected abstract void executeLowLevelRequest();
/** Get the SaveBehavior used locally for this save operation. **/
protected SaveBehavior getLocalSaveBehavior() {
return saveConfig.getSaveBehavior();
}
/** Get the table name **/
protected String getTableName() {
return tableName;
}
/** Get the map of all the specified key of the saved object. **/
protected Map<String, AttributeValue> getKeyAttributeValues() {
return key;
}
/** Get the map of AttributeValueUpdate on each modeled attribute. **/
protected Map<String, AttributeValueUpdate> getAttributeValueUpdates() {
return updateValues;
}
/**
* Merge and return all the expected value conditions (either
* user-specified or imposed by the internal implementation of
* DynamoDBMapper) for this save operation.
*/
protected Map<String, ExpectedAttributeValue> mergeExpectedAttributeValueConditions() {
return DynamoDBMapper.mergeExpectedAttributeValueConditions(
internalExpectedValueAssertions,
userProvidedExpectedValueConditions,
userProvidedConditionOperator);
}
/** Get the list of all the necessary in-memory update on the object. **/
protected List<ValueUpdate> getInMemoryUpdates() {
return inMemoryUpdates;
}
/**
* Save the item using a UpdateItem request. The handler will call this
* method if
* <ul>
* <li>CLOBBER configuration is not being used;
* <li>AND the item does not contain auto-generated key value;
* </ul>
* <p>
* The ReturnedValues parameter for the UpdateItem request is set as
* ALL_NEW, which means the service should return all of the attributes
* of the new version of the item after the update. The handler will use
* the returned attributes to detect silent failure on the server-side.
*/
protected UpdateItemResult doUpdateItem() {
UpdateItemRequest req = new UpdateItemRequest()
.withTableName(getTableName())
.withKey(getKeyAttributeValues())
.withAttributeUpdates(
transformAttributeUpdates(
this.clazz,
getTableName(),
getKeyAttributeValues(),
getAttributeValueUpdates(),
saveConfig))
.withExpected(mergeExpectedAttributeValueConditions())
.withConditionalOperator(userProvidedConditionOperator)
.withReturnValues(ReturnValue.ALL_NEW)
.withRequestMetricCollector(saveConfig.getRequestMetricCollector());
return db.updateItem(applyUserAgent(req));
}
/**
* Save the item using a PutItem request. The handler will call this
* method if
* <ul>
* <li>CLOBBER configuration is being used;
* <li>OR the item contains auto-generated key value;
* <li>OR an UpdateItem request has silently failed (200 response with
* no affected attribute), which indicates the key-only-put scenario
* that we used to handle by the keyOnlyPut(...) hack.
* </ul>
*/
protected PutItemResult doPutItem() {
Map<String, AttributeValue> attributeValues = convertToItem(getAttributeValueUpdates());
attributeValues = transformAttributes(
toParameters(attributeValues,
this.clazz,
getTableName(),
saveConfig));
PutItemRequest req = new PutItemRequest()
.withTableName(getTableName())
.withItem(attributeValues)
.withExpected(mergeExpectedAttributeValueConditions())
.withConditionalOperator(userProvidedConditionOperator)
.withRequestMetricCollector(saveConfig.getRequestMetricCollector());
return db.putItem(applyUserAgent(req));
}
private void onAutoGenerateAssignableKey(Method method, String attributeName) {
AttributeValue newVersionValue = getAutoGeneratedKeyAttributeValue(converter, method);
updateValues.put(attributeName,
new AttributeValueUpdate().withAction("PUT").withValue(newVersionValue));
inMemoryUpdates.add(new ValueUpdate(method, newVersionValue, object, converter));
if (getLocalSaveBehavior() != SaveBehavior.CLOBBER
&& !internalExpectedValueAssertions.containsKey(attributeName)) {
// Add an expect clause to make sure that the item
// doesn't already exist, since it's supposed to be new
ExpectedAttributeValue expected = new ExpectedAttributeValue();
expected.setExists(false);
internalExpectedValueAssertions.put(attributeName, expected);
}
}
private void onVersionAttribute(Method method, Object getterResult,
String attributeName) {
if (getLocalSaveBehavior() != SaveBehavior.CLOBBER
&& !internalExpectedValueAssertions.containsKey(attributeName)) {
// First establish the expected (current) value for the
// update call
ExpectedAttributeValue expected = new ExpectedAttributeValue();
// For new objects, insist that the value doesn't exist.
// For existing ones, insist it has the old value.
AttributeValue currentValue = converter.convert(method, getterResult);
expected.setExists(currentValue != null);
if (currentValue != null) {
expected.setValue(currentValue);
}
internalExpectedValueAssertions.put(attributeName, expected);
}
Object newVersion = incrementor.increment(method, getterResult);
AttributeValue newVersionValue = converter.convert(method, newVersion);
updateValues.put(attributeName, new AttributeValueUpdate()
.withAction("PUT")
.withValue(newVersionValue));
inMemoryUpdates.add(new ValueUpdate(method, newVersionValue, object, converter));
}
}
/**
* Deletes the given object from its DynamoDB table using the default
* configuration.
*/
public void delete(Object object) {
delete(object, null, this.config);
}
/**
* Deletes the given object from its DynamoDB table using the specified
* deleteExpression and default configuration.
*/
public void delete(Object object, DynamoDBDeleteExpression deleteExpression) {
delete(object, deleteExpression, this.config);
}
/**
* Deletes the given object from its DynamoDB table using the specified
* configuration.
*/
public void delete(Object object, DynamoDBMapperConfig config) {
delete(object, null, config);
}
/**
* Deletes the given object from its DynamoDB table using the provided
* deleteExpression and provided configuration. Any options specified in the
* deleteExpression parameter will be overlaid on any constraints due to
* versioned attributes.
*
* @param deleteExpression The options to apply to this delete request
* @param config Config override object. If {@link SaveBehavior#CLOBBER} is
* supplied, version fields will not be considered when deleting
* the object.
*/
public <T> void delete(T object, DynamoDBDeleteExpression deleteExpression,
DynamoDBMapperConfig config) {
config = mergeConfig(config);
ItemConverter converter = getConverter(config);
@SuppressWarnings("unchecked")
Class<T> clazz = (Class<T>) object.getClass();
String tableName = getTableName(clazz, object, config);
Map<String, AttributeValue> key = getKey(converter, object, clazz);
/*
* If there is a version field, make sure we assert its value. If the
* version field is null (only should happen in unusual circumstances),
* pretend it doesn't have a version field after all.
*/
Map<String, ExpectedAttributeValue> internalAssertions = new HashMap<String, ExpectedAttributeValue>();
if (config.getSaveBehavior() != SaveBehavior.CLOBBER) {
for (Method method : reflector.getRelevantGetters(clazz)) {
if (reflector.isVersionAttributeGetter(method)) {
Object getterResult = ReflectionUtils.safeInvoke(method, object);
String attributeName = reflector.getAttributeName(method);
ExpectedAttributeValue expected = new ExpectedAttributeValue();
AttributeValue currentValue = converter.convert(method, getterResult);
expected.setExists(currentValue != null);
if (currentValue != null)
expected.setValue(currentValue);
internalAssertions.put(attributeName, expected);
break;
}
}
}
DeleteItemRequest req = new DeleteItemRequest().withKey(key)
.withTableName(tableName).withExpected(internalAssertions)
.withRequestMetricCollector(config.getRequestMetricCollector());
if (deleteExpression != null) {
String conditionalExpression = deleteExpression.getConditionExpression();
if (conditionalExpression != null) {
if (internalAssertions != null && !internalAssertions.isEmpty()) {
throw new AmazonClientException(
"Condition Expressions cannot be used if a versioned attribute is present");
}
req = req
.withConditionExpression(conditionalExpression)
.withExpressionAttributeNames(
deleteExpression.getExpressionAttributeNames())
.withExpressionAttributeValues(
deleteExpression.getExpressionAttributeValues());
}
req = req.withExpected(
mergeExpectedAttributeValueConditions(internalAssertions,
deleteExpression.getExpected(),
deleteExpression.getConditionalOperator()))
.withConditionalOperator(
deleteExpression.getConditionalOperator());
}
db.deleteItem(applyUserAgent(req));
}
/**
* Deletes the objects given using one or more calls to the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)} API. <b>No
* version checks are performed</b>, as required by the API.
*
* @see DynamoDBMapper#batchWrite(List, List, DynamoDBMapperConfig)
*/
public List<FailedBatch> batchDelete(List<? extends Object> objectsToDelete) {
return batchWrite(Collections.emptyList(), objectsToDelete, this.config);
}
/**
* Deletes the objects given using one or more calls to the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)} API. <b>No
* version checks are performed</b>, as required by the API.
*
* @see DynamoDBMapper#batchWrite(List, List, DynamoDBMapperConfig)
*/
public List<FailedBatch> batchDelete(Object... objectsToDelete) {
return batchWrite(Collections.emptyList(), Arrays.asList(objectsToDelete), this.config);
}
/**
* Saves the objects given using one or more calls to the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)} API. <b>No
* version checks are performed</b>, as required by the API.
* <p/>
* <b>This method ignores any SaveBehavior set on the mapper</b>, and always
* behaves as if SaveBehavior.CLOBBER was specified, as the
* AmazonDynamoDB.batchWriteItem() request does not support updating
* existing items.
* <p>
* This method fails to save the batch if the size of an individual object
* in the batch exceeds 400 KB. For more information on batch restrictions
* see, http://docs.aws.amazon
* .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html
* </p>
*
* @see DynamoDBMapper#batchWrite(List, List, DynamoDBMapperConfig)
*/
public List<FailedBatch> batchSave(List<? extends Object> objectsToSave) {
return batchWrite(objectsToSave, Collections.emptyList(), this.config);
}
/**
* Saves the objects given using one or more calls to the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)} API. <b>No
* version checks are performed</b>, as required by the API.
* <p/>
* <b>This method ignores any SaveBehavior set on the mapper</b>, and always
* behaves as if SaveBehavior.CLOBBER was specified, as the
* AmazonDynamoDB.batchWriteItem() request does not support updating
* existing items. *
* <p>
* This method fails to save the batch if the size of an individual object
* in the batch exceeds 400 KB. For more information on batch restrictions
* see, http://docs.aws.amazon
* .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html
* </p>
*
* @see DynamoDBMapper#batchWrite(List, List, DynamoDBMapperConfig)
*/
public List<FailedBatch> batchSave(Object... objectsToSave) {
return batchWrite(Arrays.asList(objectsToSave), Collections.emptyList(), this.config);
}
/**
* Saves and deletes the objects given using one or more calls to the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)} API. <b>No
* version checks are performed</b>, as required by the API.
* <p/>
* <b>This method ignores any SaveBehavior set on the mapper</b>, and always
* behaves as if SaveBehavior.CLOBBER was specified, as the
* AmazonDynamoDB.batchWriteItem() request does not support updating
* existing items.
* <p>
* This method fails to save the batch if the size of an individual object
* in the batch exceeds 400 KB. For more information on batch restrictions
* see, http://docs.aws.amazon
* .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html
* </p>
*
* @see DynamoDBMapper#batchWrite(List, List, DynamoDBMapperConfig)
*/
public List<FailedBatch> batchWrite(List<? extends Object> objectsToWrite,
List<? extends Object> objectsToDelete) {
return batchWrite(objectsToWrite, objectsToDelete, this.config);
}
/**
* Saves and deletes the objects given using one or more calls to the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)} API.
* <p>
* This method fails to save the batch if the size of an individual object
* in the batch exceeds 400 KB. For more information on batch restrictions
* see, http://docs.aws.amazon
* .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html
* </p>
*
* @param objectsToWrite A list of objects to save to DynamoDB. <b>No
* version checks are performed</b>, as required by the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)}
* API.
* @param objectsToDelete A list of objects to delete from DynamoDB. <b>No
* version checks are performed</b>, as required by the
* {@link AmazonDynamoDB#batchWriteItem(BatchWriteItemRequest)}
* API.
* @param config Only {@link DynamoDBMapperConfig#getTableNameOverride()} is
* considered; if specified, all objects in the two parameter
* lists will be considered to belong to the given table
* override. In particular, this method <b>always acts as if
* SaveBehavior.CLOBBER was specified</b> regardless of the value
* of the config parameter.
* @return A list of failed batches which includes the unprocessed items and
* the exceptions causing the failure.
*/
public List<FailedBatch> batchWrite(List<? extends Object> objectsToWrite,
List<? extends Object> objectsToDelete, DynamoDBMapperConfig config) {
config = mergeConfig(config);
List<FailedBatch> totalFailedBatches = new LinkedList<FailedBatch>();
HashMap<String, List<WriteRequest>> requestItems = new HashMap<String, List<WriteRequest>>();
ItemConverter converter = getConverter(config);
List<ValueUpdate> inMemoryUpdates = new LinkedList<ValueUpdate>();
for (Object toWrite : objectsToWrite) {
Class<?> clazz = toWrite.getClass();
String tableName = getTableName(clazz, toWrite, config);
Map<String, AttributeValue> attributeValues = new HashMap<String, AttributeValue>();
// Look at every getter and construct a value object for it
for (Method method : reflector.getRelevantGetters(clazz)) {
Object getterResult =
ReflectionUtils.safeInvoke(method, toWrite);
String attributeName = reflector.getAttributeName(method);
AttributeValue currentValue = null;
if (getterResult == null && reflector.isAssignableKey(method)) {
currentValue = getAutoGeneratedKeyAttributeValue(converter, method);
inMemoryUpdates.add(new ValueUpdate(method, currentValue, toWrite, converter));
} else {
currentValue = converter.convert(method, getterResult);
}
if (currentValue != null) {
attributeValues.put(attributeName, currentValue);
}
}
if (!requestItems.containsKey(tableName)) {
requestItems.put(tableName, new LinkedList<WriteRequest>());
}
AttributeTransformer.Parameters<?> parameters =
toParameters(attributeValues, clazz, tableName, config);
requestItems.get(tableName).add(
new WriteRequest().withPutRequest(
new PutRequest().withItem(
transformAttributes(parameters))));
}
for (Object toDelete : objectsToDelete) {
Class<?> clazz = toDelete.getClass();
String tableName = getTableName(clazz, toDelete, config);
Map<String, AttributeValue> key = getKey(converter, toDelete);
if (!requestItems.containsKey(tableName)) {
requestItems.put(tableName, new LinkedList<WriteRequest>());
}
requestItems.get(tableName).add(
new WriteRequest().withDeleteRequest(new DeleteRequest().withKey(key)));
}
// Break into chunks of 25 items and make service requests to DynamoDB
while (!requestItems.isEmpty()) {
HashMap<String, List<WriteRequest>> batch =
new HashMap<String, List<WriteRequest>>();
int i = 0;
Iterator<Entry<String, List<WriteRequest>>> tableIter = requestItems.entrySet()
.iterator();
while (tableIter.hasNext() && i < MAX_ITEMS_PER_BATCH) {
Entry<String, List<WriteRequest>> tableRequest = tableIter.next();
batch.put(tableRequest.getKey(), new LinkedList<WriteRequest>());
Iterator<WriteRequest> writeRequestIter = tableRequest.getValue().iterator();
while (writeRequestIter.hasNext() && i++ < MAX_ITEMS_PER_BATCH) {
WriteRequest writeRequest = writeRequestIter.next();
batch.get(tableRequest.getKey()).add(writeRequest);
writeRequestIter.remove();
}
// If we've processed all the write requests for this table,
// remove it from the parent iterator.
if (!writeRequestIter.hasNext()) {
tableIter.remove();
}
}
List<FailedBatch> failedBatches = writeOneBatch(batch);
if (failedBatches != null) {
totalFailedBatches.addAll(failedBatches);
// If contains throttling exception, we do a backoff
if (containsThrottlingException(failedBatches)) {
try {
Thread.sleep(1000 * 2);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new AmazonClientException(e.getMessage(), e);
}
}
}
}
// Once the entire batch is processed, update assigned keys in memory
for (ValueUpdate update : inMemoryUpdates) {
update.apply();
}
return totalFailedBatches;
}
/**
* Process one batch of requests(max 25). It will divide the batch if
* receives request too large exception(the total size of the request is
* beyond 1M).
*/
List<FailedBatch> writeOneBatch(Map<String, List<WriteRequest>> batch) {
List<FailedBatch> failedBatches = new LinkedList<FailedBatch>();
Map<String, List<WriteRequest>> firstHalfBatch = new HashMap<String, List<WriteRequest>>();
Map<String, List<WriteRequest>> secondHalfBatch = new HashMap<String, List<WriteRequest>>();
FailedBatch failedBatch = callUntilCompletion(batch);
if (failedBatch != null) {
// If the exception is request entity too large, we divide the batch
// into smaller parts.
if (failedBatch.getException() instanceof AmazonServiceException
&& RetryUtils
.isRequestEntityTooLargeException((AmazonServiceException) failedBatch
.getException())) {
// If only one item left, the item size must beyond 64k, which
// exceedes the limit.
if (computeFailedBatchSize(failedBatch) == 1) {
failedBatches.add(failedBatch);
} else {
divideBatch(batch, firstHalfBatch, secondHalfBatch);
failedBatches.addAll(writeOneBatch(firstHalfBatch));
failedBatches.addAll(writeOneBatch(secondHalfBatch));
}
} else {
failedBatches.add(failedBatch);
}
}
return failedBatches;
}
/**
* Check whether there are throttling exception in the failed batches.
*/
boolean containsThrottlingException(List<FailedBatch> failedBatches) {
for (FailedBatch failedBatch : failedBatches) {
Exception e = failedBatch.getException();
if (e instanceof AmazonServiceException
&& RetryUtils.isThrottlingException((AmazonServiceException) e)) {
return true;
}
}
return false;
}
/**
* Divide the batch of objects to save into two smaller batches. Each
* contains half of the elements.
*/
private void divideBatch(Map<String, List<WriteRequest>> batch,
Map<String, List<WriteRequest>> firstHalfBatch,
Map<String, List<WriteRequest>> secondHalfBatch) {
for (String key : batch.keySet()) {
List<WriteRequest> requests = batch.get(key);
List<WriteRequest> firstHalfRequests = requests.subList(0, requests.size() / 2);
List<WriteRequest> secondHalfRequests = requests.subList(requests.size() / 2,
requests.size());
firstHalfBatch.put(key, firstHalfRequests);
secondHalfBatch.put(key, secondHalfRequests);
}
}
/**
* Count the total number of unprocessed items in the failed batch.
*/
private int computeFailedBatchSize(FailedBatch failedBatch) {
int count = 0;
for (String tableName : failedBatch.getUnprocessedItems().keySet()) {
count += failedBatch.getUnprocessedItems().get(tableName).size();
}
return count;
}
/**
* Continue trying to process the batch until it finishes or an exception
* occurs.
*/
private FailedBatch callUntilCompletion(Map<String, List<WriteRequest>> batch) {
BatchWriteItemResult result = null;
int retries = 0;
FailedBatch failedBatch = null;
while (true) {
try {
result = db.batchWriteItem(applyBatchOperationUserAgent(
new BatchWriteItemRequest().withRequestItems(batch)));
} catch (Exception e) {
failedBatch = new FailedBatch();
failedBatch.setUnprocessedItems(batch);
failedBatch.setException(e);
return failedBatch;
}
retries++;
batch = result.getUnprocessedItems();
if (batch.size() > 0) {
pauseExponentially(retries);
} else {
break;
}
}
return failedBatch;
}
/**
* Retrieves multiple items from multiple tables using their primary keys.
*
* @see DynamoDBMapper#batchLoad(List, DynamoDBMapperConfig)
* @return A map of the loaded objects. Each key in the map is the name of a
* DynamoDB table. Each value in the map is a list of objects that
* have been loaded from that table. All objects for each table can
* be cast to the associated user defined type that is annotated as
* mapping that table.
*/
public Map<String, List<Object>> batchLoad(List<Object> itemsToGet) {
return batchLoad(itemsToGet, this.config);
}
/**
* Retrieves multiple items from multiple tables using their primary keys.
*
* @param itemsToGet Key objects, corresponding to the class to fetch, with
* their primary key values set.
* @param config Only {@link DynamoDBMapperConfig#getTableNameOverride()}
* and {@link DynamoDBMapperConfig#getConsistentReads()} are
* considered.
* @return A map of the loaded objects. Each key in the map is the name of a
* DynamoDB table. Each value in the map is a list of objects that
* have been loaded from that table. All objects for each table can
* be cast to the associated user defined type that is annotated as
* mapping that table.
*/
public Map<String, List<Object>> batchLoad(List<Object> itemsToGet, DynamoDBMapperConfig config) {
config = mergeConfig(config);
boolean consistentReads = (config.getConsistentReads() == ConsistentReads.CONSISTENT);
if (itemsToGet == null || itemsToGet.isEmpty()) {
return new HashMap<String, List<Object>>();
}
Map<String, KeysAndAttributes> requestItems = new HashMap<String, KeysAndAttributes>();
Map<String, Class<?>> classesByTableName = new HashMap<String, Class<?>>();
Map<String, List<Object>> resultSet = new HashMap<String, List<Object>>();
int count = 0;
ItemConverter converter = getConverter(config);
for (Object keyObject : itemsToGet) {
Class<?> clazz = keyObject.getClass();
String tableName = getTableName(clazz, keyObject, config);
classesByTableName.put(tableName, clazz);
if (!requestItems.containsKey(tableName)) {
requestItems.put(
tableName,
new KeysAndAttributes().withConsistentRead(consistentReads).withKeys(
new LinkedList<Map<String, AttributeValue>>()));
}
requestItems.get(tableName).getKeys().add(
getKey(converter, keyObject));
// Reach the maximum number which can be handled in a single
// batchGet
if (++count == 100) {
processBatchGetRequest(classesByTableName, requestItems, resultSet, config,
converter);
requestItems.clear();
count = 0;
}
}
if (count > 0) {
processBatchGetRequest(classesByTableName, requestItems, resultSet, config, converter);
}
return resultSet;
}
/**
* Retrieves the attributes for multiple items from multiple tables using
* their primary keys.
* {@link AmazonDynamoDB#batchGetItem(BatchGetItemRequest)} API.
*
* @return A map of the loaded objects. Each key in the map is the name of a
* DynamoDB table. Each value in the map is a list of objects that
* have been loaded from that table. All objects for each table can
* be cast to the associated user defined type that is annotated as
* mapping that table.
* @see #batchLoad(List, DynamoDBMapperConfig)
* @see #batchLoad(Map, DynamoDBMapperConfig)
*/
public Map<String, List<Object>> batchLoad(Map<Class<?>, List<KeyPair>> itemsToGet) {
return batchLoad(itemsToGet, this.config);
}
/**
* Retrieves multiple items from multiple tables using their primary keys.
* Valid only for tables with a single hash key, or a single hash and range
* key. For other schemas, use
* {@link DynamoDBMapper#batchLoad(List, DynamoDBMapperConfig)}
*
* @param itemsToGet Map from class to load to list of primary key
* attributes.
* @param config Only {@link DynamoDBMapperConfig#getTableNameOverride()}
* and {@link DynamoDBMapperConfig#getConsistentReads()} are
* considered.
* @return A map of the loaded objects. Each key in the map is the name of a
* DynamoDB table. Each value in the map is a list of objects that
* have been loaded from that table. All objects for each table can
* be cast to the associated user defined type that is annotated as
* mapping that table.
*/
public Map<String, List<Object>> batchLoad(Map<Class<?>, List<KeyPair>> itemsToGet,
DynamoDBMapperConfig config) {
List<Object> keys = new ArrayList<Object>();
if (itemsToGet != null) {
for (Class<?> clazz : itemsToGet.keySet()) {
if (itemsToGet.get(clazz) != null) {
for (KeyPair keyPair : itemsToGet.get(clazz)) {
keys.add(createKeyObject(clazz, keyPair.getHashKey(), keyPair.getRangeKey()));
}
}
}
}
return batchLoad(keys, config);
}
/**
* @param config never null
*/
private void processBatchGetRequest(
final Map<String, Class<?>> classesByTableName,
final Map<String, KeysAndAttributes> requestItems,
final Map<String, List<Object>> resultSet,
final DynamoDBMapperConfig config,
final ItemConverter converter) {
BatchGetItemResult batchGetItemResult = null;
BatchGetItemRequest batchGetItemRequest = new BatchGetItemRequest()
.withRequestMetricCollector(config.getRequestMetricCollector());
batchGetItemRequest.setRequestItems(requestItems);
int retries = 0;
do {
if (batchGetItemResult != null) {
retries++;
pauseExponentially(retries);
if (retries > BATCH_GET_MAX_RETRY_COUNT_ALL_KEYS) {
throw new AmazonClientException(
"Batch Get Item request to server hasn't received any data. "
+ "Please try again later.");
}
batchGetItemRequest.setRequestItems(
batchGetItemResult.getUnprocessedKeys());
}
batchGetItemResult = db.batchGetItem(
applyBatchOperationUserAgent(batchGetItemRequest));
Map<String, List<Map<String, AttributeValue>>> responses = batchGetItemResult
.getResponses();
for (String tableName : responses.keySet()) {
List<Object> objects = null;
if (resultSet.get(tableName) != null) {
objects = resultSet.get(tableName);
} else {
objects = new LinkedList<Object>();
}
Class<?> clazz = classesByTableName.get(tableName);
for (Map<String, AttributeValue> item : responses.get(tableName)) {
AttributeTransformer.Parameters<?> parameters =
toParameters(item, clazz, tableName, config);
objects.add(privateMarshallIntoObject(converter, parameters));
}
resultSet.put(tableName, objects);
}
// To see whether there are unprocessed keys.
} while (batchGetItemResult.getUnprocessedKeys() != null
&& batchGetItemResult.getUnprocessedKeys().size() > 0);
}
private final class ValueUpdate {
private final Method method;
private final AttributeValue newValue;
private final Object target;
private final ItemConverter converter;
public ValueUpdate(
Method method,
AttributeValue newValue,
Object target,
ItemConverter converter) {
this.method = method;
this.newValue = newValue;
this.target = target;
this.converter = converter;
}
public void apply() {
Method setter = reflector.getSetter(method);
Object pojo = converter.unconvert(method, setter, newValue);
ReflectionUtils.safeInvoke(setter, target, pojo);
}
}
/**
* Converts the {@link AttributeValueUpdate} map given to an equivalent
* {@link AttributeValue} map.
*/
private Map<String, AttributeValue> convertToItem(Map<String, AttributeValueUpdate> putValues) {
Map<String, AttributeValue> map = new HashMap<String, AttributeValue>();
for (Entry<String, AttributeValueUpdate> entry : putValues.entrySet()) {
String attributeName = entry.getKey();
AttributeValue attributeValue = entry.getValue().getValue();
String attributeAction = entry.getValue().getAction();
/*
* AttributeValueUpdate allows nulls for its values, since they are
* semantically meaningful. AttributeValues never have null values.
*/
if (attributeValue != null
&& !AttributeAction.DELETE.toString().equals(attributeAction)) {
map.put(attributeName, attributeValue);
}
}
return map;
}
private AttributeValue getAutoGeneratedKeyAttributeValue(
ItemConverter converter,
Method getter) {
Class<?> returnType = getter.getReturnType();
if (String.class.isAssignableFrom(returnType)) {
return converter.convert(getter, UUID.randomUUID().toString());
}
throw new DynamoDBMappingException(
"Unsupported type for " + getter + ": " + returnType
+ ". Only Strings are supported when auto-generating keys.");
}
/**
* Scans through an Amazon DynamoDB table and returns the matching results
* as an unmodifiable list of instantiated objects, using the default
* configuration.
*
* @see DynamoDBMapper#scan(Class, DynamoDBScanExpression,
* DynamoDBMapperConfig)
*/
public <T> PaginatedScanList<T> scan(Class<T> clazz, DynamoDBScanExpression scanExpression) {
return scan(clazz, scanExpression, config);
}
/**
* Scans through an Amazon DynamoDB table and returns the matching results
* as an unmodifiable list of instantiated objects. The table to scan is
* determined by looking at the annotations on the specified class, which
* declares where to store the object data in Amazon DynamoDB, and the scan
* expression parameter allows the caller to filter results and control how
* the scan is executed.
* <p>
* Callers should be aware that the returned list is unmodifiable, and any
* attempts to modify the list will result in an
* UnsupportedOperationException.
* <p>
* You can specify the pagination loading strategy for this scan operation.
* By default, the list returned is lazily loaded when possible.
*
* @param <T> The type of the objects being returned.
* @param clazz The class annotated with DynamoDB annotations describing how
* to store the object data in Amazon DynamoDB.
* @param scanExpression Details on how to run the scan, including any
* filters to apply to limit results.
* @param config The configuration to use for this scan, which overrides the
* default provided at object construction.
* @return An unmodifiable list of the objects constructed from the results
* of the scan operation.
* @see PaginatedScanList
* @see PaginationLoadingStrategy
*/
public <T> PaginatedScanList<T> scan(Class<T> clazz, DynamoDBScanExpression scanExpression,
DynamoDBMapperConfig config) {
config = mergeConfig(config);
ScanRequest scanRequest = createScanRequestFromExpression(clazz, scanExpression, config);
ScanResult scanResult = db.scan(applyUserAgent(scanRequest));
return new PaginatedScanList<T>(this, clazz, db, scanRequest, scanResult,
config.getPaginationLoadingStrategy(), config);
}
/**
* Scans through an Amazon DynamoDB table on logically partitioned segments
* in parallel and returns the matching results in one unmodifiable list of
* instantiated objects, using the default configuration.
*
* @see DynamoDBMapper#parallelScan(Class, DynamoDBScanExpression,int,
* DynamoDBMapperConfig)
*/
public <T> PaginatedParallelScanList<T> parallelScan(Class<T> clazz,
DynamoDBScanExpression scanExpression, int totalSegments) {
return parallelScan(clazz, scanExpression, totalSegments, config);
}
/**
* Scans through an Amazon DynamoDB table on logically partitioned segments
* in parallel. This method will create a thread pool of the specified size,
* and each thread will issue scan requests for its assigned segment,
* following the returned continuation token, until the end of its segment.
* Callers should be responsible for setting the appropriate number of total
* segments. More scan segments would result in better performance but more
* consumed capacity of the table. The results are returned in one
* unmodifiable list of instantiated objects. The table to scan is
* determined by looking at the annotations on the specified class, which
* declares where to store the object data in Amazon DynamoDB, and the scan
* expression parameter allows the caller to filter results and control how
* the scan is executed.
* <p>
* Callers should be aware that the returned list is unmodifiable, and any
* attempts to modify the list will result in an
* UnsupportedOperationException.
* <p>
* You can specify the pagination loading strategy for this parallel scan
* operation. By default, the list returned is lazily loaded when possible.
*
* @param <T> The type of the objects being returned.
* @param clazz The class annotated with DynamoDB annotations describing how
* to store the object data in Amazon DynamoDB.
* @param scanExpression Details on how to run the scan, including any
* filters to apply to limit results.
* @param totalSegments Number of total parallel scan segments. <b>Range:
* </b>1 - 4096
* @param config The configuration to use for this scan, which overrides the
* default provided at object construction.
* @return An unmodifiable list of the objects constructed from the results
* of the scan operation.
* @see PaginatedParallelScanList
* @see PaginationLoadingStrategy
*/
public <T> PaginatedParallelScanList<T> parallelScan(Class<T> clazz,
DynamoDBScanExpression scanExpression, int totalSegments, DynamoDBMapperConfig config) {
config = mergeConfig(config);
// Create hard copies of the original scan request with difference
// segment number.
List<ScanRequest> parallelScanRequests = createParallelScanRequestsFromExpression(clazz,
scanExpression, totalSegments, config);
ParallelScanTask parallelScanTask = new ParallelScanTask(this, db, parallelScanRequests);
return new PaginatedParallelScanList<T>(this, clazz, db, parallelScanTask,
config.getPaginationLoadingStrategy(), config);
}
/**
* Scans through an Amazon DynamoDB table and returns a single page of
* matching results. The table to scan is determined by looking at the
* annotations on the specified class, which declares where to store the
* object data in AWS DynamoDB, and the scan expression parameter allows the
* caller to filter results and control how the scan is executed.
*
* @param <T> The type of the objects being returned.
* @param clazz The class annotated with DynamoDB annotations describing how
* to store the object data in Amazon DynamoDB.
* @param scanExpression Details on how to run the scan, including any
* filters to apply to limit results.
* @param config The configuration to use for this scan, which overrides the
* default provided at object construction.
*/
public <T> ScanResultPage<T> scanPage(Class<T> clazz, DynamoDBScanExpression scanExpression,
DynamoDBMapperConfig config) {
config = mergeConfig(config);
ScanRequest scanRequest = createScanRequestFromExpression(clazz, scanExpression, config);
ScanResult scanResult = db.scan(applyUserAgent(scanRequest));
ScanResultPage<T> result = new ScanResultPage<T>();
List<AttributeTransformer.Parameters<T>> parameters =
toParameters(scanResult.getItems(), clazz, scanRequest.getTableName(), config);
result.setResults(marshallIntoObjects(parameters));
result.setLastEvaluatedKey(scanResult.getLastEvaluatedKey());
return result;
}
/**
* Scans through an Amazon DynamoDB table and returns a single page of
* matching results.
*
* @see DynamoDBMapper#scanPage(Class, DynamoDBScanExpression,
* DynamoDBMapperConfig)
*/
public <T> ScanResultPage<T> scanPage(Class<T> clazz, DynamoDBScanExpression scanExpression) {
return scanPage(clazz, scanExpression, this.config);
}
/**
* Queries an Amazon DynamoDB table and returns the matching results as an
* unmodifiable list of instantiated objects, using the default
* configuration.
*
* @see DynamoDBMapper#query(Class, DynamoDBQueryExpression,
* DynamoDBMapperConfig)
*/
public <T> PaginatedQueryList<T> query(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression) {
return query(clazz, queryExpression, config);
}
/**
* Queries an Amazon DynamoDB table and returns the matching results as an
* unmodifiable list of instantiated objects. The table to query is
* determined by looking at the annotations on the specified class, which
* declares where to store the object data in Amazon DynamoDB, and the query
* expression parameter allows the caller to filter results and control how
* the query is executed.
* <p>
* When the query is on any local/global secondary index, callers should be
* aware that the returned object(s) will only contain item attributes that
* are projected into the index. All the other unprojected attributes will
* be saved as type default values.
* <p>
* Callers should also be aware that the returned list is unmodifiable, and
* any attempts to modify the list will result in an
* UnsupportedOperationException.
* <p>
* You can specify the pagination loading strategy for this query operation.
* By default, the list returned is lazily loaded when possible.
*
* @param <T> The type of the objects being returned.
* @param clazz The class annotated with DynamoDB annotations describing how
* to store the object data in Amazon DynamoDB.
* @param queryExpression Details on how to run the query, including any
* conditions on the key values
* @param config The configuration to use for this query, which overrides
* the default provided at object construction.
* @return An unmodifiable list of the objects constructed from the results
* of the query operation.
* @see PaginatedQueryList
* @see PaginationLoadingStrategy
*/
public <T> PaginatedQueryList<T> query(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression, DynamoDBMapperConfig config) {
config = mergeConfig(config);
QueryRequest queryRequest = createQueryRequestFromExpression(clazz, queryExpression, config);
QueryResult queryResult = db.query(applyUserAgent(queryRequest));
return new PaginatedQueryList<T>(this, clazz, db, queryRequest, queryResult,
config.getPaginationLoadingStrategy(), config);
}
/**
* Queries an Amazon DynamoDB table and returns a single page of matching
* results. The table to query is determined by looking at the annotations
* on the specified class, which declares where to store the object data in
* Amazon DynamoDB, and the query expression parameter allows the caller to
* filter results and control how the query is executed.
*
* @see DynamoDBMapper#queryPage(Class, DynamoDBQueryExpression,
* DynamoDBMapperConfig)
*/
public <T> QueryResultPage<T> queryPage(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression) {
return queryPage(clazz, queryExpression, this.config);
}
/**
* Queries an Amazon DynamoDB table and returns a single page of matching
* results. The table to query is determined by looking at the annotations
* on the specified class, which declares where to store the object data in
* Amazon DynamoDB, and the query expression parameter allows the caller to
* filter results and control how the query is executed.
*
* @param <T> The type of the objects being returned.
* @param clazz The class annotated with DynamoDB annotations describing how
* to store the object data in AWS DynamoDB.
* @param queryExpression Details on how to run the query, including any
* conditions on the key values
* @param config The configuration to use for this query, which overrides
* the default provided at object construction.
*/
public <T> QueryResultPage<T> queryPage(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression, DynamoDBMapperConfig config) {
config = mergeConfig(config);
QueryRequest queryRequest = createQueryRequestFromExpression(clazz, queryExpression, config);
QueryResult scanResult = db.query(applyUserAgent(queryRequest));
QueryResultPage<T> result = new QueryResultPage<T>();
List<AttributeTransformer.Parameters<T>> parameters =
toParameters(scanResult.getItems(), clazz, queryRequest.getTableName(), config);
result.setResults(marshallIntoObjects(parameters));
result.setLastEvaluatedKey(scanResult.getLastEvaluatedKey());
return result;
}
/**
* Evaluates the specified scan expression and returns the count of matching
* items, without returning any of the actual item data, using the default
* configuration.
*
* @see DynamoDBMapper#count(Class, DynamoDBScanExpression,
* DynamoDBMapperConfig)
*/
public int count(Class<?> clazz, DynamoDBScanExpression scanExpression) {
return count(clazz, scanExpression, config);
}
/**
* Evaluates the specified scan expression and returns the count of matching
* items, without returning any of the actual item data.
* <p>
* This operation will scan your entire table, and can therefore be very
* expensive. Use with caution.
*
* @param clazz The class mapped to a DynamoDB table.
* @param scanExpression The parameters for running the scan.
* @param config The configuration to use for this scan, which overrides the
* default provided at object construction.
* @return The count of matching items, without returning any of the actual
* item data.
*/
public int count(Class<?> clazz, DynamoDBScanExpression scanExpression,
DynamoDBMapperConfig config) {
config = mergeConfig(config);
ScanRequest scanRequest = createScanRequestFromExpression(clazz, scanExpression, config);
scanRequest.setSelect(Select.COUNT);
// Count scans can also be truncated for large datasets
int count = 0;
ScanResult scanResult = null;
do {
scanResult = db.scan(applyUserAgent(scanRequest));
count += scanResult.getCount();
scanRequest.setExclusiveStartKey(scanResult.getLastEvaluatedKey());
} while (scanResult.getLastEvaluatedKey() != null);
return count;
}
/**
* Evaluates the specified query expression and returns the count of
* matching items, without returning any of the actual item data, using the
* default configuration.
*
* @see DynamoDBMapper#count(Class, DynamoDBQueryExpression,
* DynamoDBMapperConfig)
*/
public <T> int count(Class<T> clazz, DynamoDBQueryExpression<T> queryExpression) {
return count(clazz, queryExpression, config);
}
/**
* Evaluates the specified query expression and returns the count of
* matching items, without returning any of the actual item data.
*
* @param clazz The class mapped to a DynamoDB table.
* @param queryExpression The parameters for running the scan.
* @param config The mapper configuration to use for the query, which
* overrides the default provided at object construction.
* @return The count of matching items, without returning any of the actual
* item data.
*/
public <T> int count(Class<T> clazz, DynamoDBQueryExpression<T> queryExpression,
DynamoDBMapperConfig config) {
config = mergeConfig(config);
QueryRequest queryRequest = createQueryRequestFromExpression(clazz, queryExpression, config);
queryRequest.setSelect(Select.COUNT);
// Count queries can also be truncated for large datasets
int count = 0;
QueryResult queryResult = null;
do {
queryResult = db.query(applyUserAgent(queryRequest));
count += queryResult.getCount();
queryRequest.setExclusiveStartKey(queryResult.getLastEvaluatedKey());
} while (queryResult.getLastEvaluatedKey() != null);
return count;
}
/**
* Merges the config object given with the one specified at construction and
* returns the result.
*/
private DynamoDBMapperConfig mergeConfig(DynamoDBMapperConfig config) {
if (config != this.config)
config = new DynamoDBMapperConfig(this.config, config);
return config;
}
/**
* @param config never null
*/
ScanRequest createScanRequestFromExpression(Class<?> clazz,
DynamoDBScanExpression scanExpression, DynamoDBMapperConfig config) {
ScanRequest scanRequest = new ScanRequest();
scanRequest.setTableName(getTableName(clazz, config));
scanRequest.setScanFilter(scanExpression.getScanFilter());
scanRequest.setLimit(scanExpression.getLimit());
scanRequest.setExclusiveStartKey(scanExpression.getExclusiveStartKey());
scanRequest.setTotalSegments(scanExpression.getTotalSegments());
scanRequest.setSegment(scanExpression.getSegment());
scanRequest.setConditionalOperator(scanExpression.getConditionalOperator());
scanRequest.setFilterExpression(scanExpression.getFilterExpression());
scanRequest.setExpressionAttributeNames(scanExpression
.getExpressionAttributeNames());
scanRequest.setExpressionAttributeValues(scanExpression
.getExpressionAttributeValues());
scanRequest.setRequestMetricCollector(config.getRequestMetricCollector());
return applyUserAgent(scanRequest);
}
/**
* @param config never null
*/
List<ScanRequest> createParallelScanRequestsFromExpression(Class<?> clazz,
DynamoDBScanExpression scanExpression, int totalSegments, DynamoDBMapperConfig config) {
if (totalSegments < 1) {
throw new IllegalArgumentException(
"Parallel scan should have at least one scan segment.");
}
if (scanExpression.getExclusiveStartKey() != null) {
log.info("The ExclusiveStartKey parameter specified in the DynamoDBScanExpression is ignored,"
+ " since the individual parallel scan request on each segment is applied on a separate key scope.");
}
if (scanExpression.getSegment() != null || scanExpression.getTotalSegments() != null) {
log.info("The Segment and TotalSegments parameters specified in the DynamoDBScanExpression are ignored.");
}
List<ScanRequest> parallelScanRequests = new LinkedList<ScanRequest>();
for (int segment = 0; segment < totalSegments; segment++) {
ScanRequest scanRequest = createScanRequestFromExpression(clazz, scanExpression, config);
parallelScanRequests.add(scanRequest
.withSegment(segment).withTotalSegments(totalSegments)
.withExclusiveStartKey(null));
}
return parallelScanRequests;
}
private <T> QueryRequest createQueryRequestFromExpression(Class<T> clazz,
DynamoDBQueryExpression<T> queryExpression, DynamoDBMapperConfig config) {
QueryRequest queryRequest = new QueryRequest();
queryRequest.setConsistentRead(queryExpression.isConsistentRead());
queryRequest.setTableName(getTableName(clazz, queryExpression.getHashKeyValues(), config));
queryRequest.setIndexName(queryExpression.getIndexName());
ItemConverter converter = getConverter(config);
// Hash key (primary or index) conditions
Map<String, Condition> hashKeyConditions = getHashKeyEqualsConditions(
converter, queryExpression.getHashKeyValues());
// Range key (primary or index) conditions
Map<String, Condition> rangeKeyConditions = queryExpression.getRangeKeyConditions();
processKeyConditions(clazz, queryRequest, hashKeyConditions, rangeKeyConditions);
queryRequest.setScanIndexForward(queryExpression.isScanIndexForward());
queryRequest.setLimit(queryExpression.getLimit());
queryRequest.setExclusiveStartKey(queryExpression.getExclusiveStartKey());
queryRequest.setQueryFilter(queryExpression.getQueryFilter());
queryRequest.setConditionalOperator(queryExpression.getConditionalOperator());
queryRequest.setRequestMetricCollector(config.getRequestMetricCollector());
queryRequest.setFilterExpression(queryExpression.getFilterExpression());
queryRequest.setExpressionAttributeNames(queryExpression
.getExpressionAttributeNames());
queryRequest.setExpressionAttributeValues(queryExpression
.getExpressionAttributeValues());
return applyUserAgent(queryRequest);
}
/**
* Utility method for checking the validity of both hash and range key
* conditions. It also tries to infer the correct index name from the POJO
* annotation, if such information is not directly specified by the user.
*
* @param clazz The domain class of the queried items.
* @param queryRequest The QueryRequest object to be sent to service.
* @param hashKeyConditions All the hash key EQ conditions extracted from
* the POJO object. The mapper will choose one of them that could
* be applied together with the user-specified (if any) index
* name and range key conditions. Or it throws error if more than
* one conditions are applicable for the query.
* @param rangeKeyConditions The range conditions specified by the user. We
* currently only allow at most one range key condition.
*/
private void processKeyConditions(Class<?> clazz,
QueryRequest queryRequest,
Map<String, Condition> hashKeyConditions,
Map<String, Condition> rangeKeyConditions) {
// There should be least one hash key condition.
if (hashKeyConditions == null || hashKeyConditions.isEmpty()) {
throw new IllegalArgumentException(
"Illegal query expression: No hash key condition is found in the query");
}
// We don't allow multiple range key conditions.
if (rangeKeyConditions != null && rangeKeyConditions.size() > 1) {
throw new IllegalArgumentException(
"Illegal query expression: Conditions on multiple range keys ("
+ rangeKeyConditions.keySet().toString()
+ ") are found in the query. DynamoDB service only accepts up to ONE range key condition.");
}
final boolean hasRangeKeyCondition = (rangeKeyConditions != null)
&& (!rangeKeyConditions.isEmpty());
final String userProvidedIndexName = queryRequest.getIndexName();
final String primaryHashKeyName = reflector.getPrimaryHashKeyName(clazz);
final TableIndexesInfo parsedIndexesInfo = schemaParser.parseTableIndexes(clazz, reflector);
// First collect the names of all the global/local secondary indexes
// that could be applied to this query.
// If the user explicitly specified an index name, we also need to
// 1) check the index is applicable for both hash and range key
// conditions
// 2) choose one hash key condition if there are more than one of them
boolean hasPrimaryHashKeyCondition = false;
final Map<String, Set<String>> annotatedGSIsOnHashKeys = new HashMap<String, Set<String>>();
String hashKeyNameForThisQuery = null;
boolean hasPrimaryRangeKeyCondition = false;
final Set<String> annotatedLSIsOnRangeKey = new HashSet<String>();
final Set<String> annotatedGSIsOnRangeKey = new HashSet<String>();
// Range key condition
String rangeKeyNameForThisQuery = null;
if (hasRangeKeyCondition) {
for (String rangeKeyName : rangeKeyConditions.keySet()) {
rangeKeyNameForThisQuery = rangeKeyName;
if (reflector.hasPrimaryRangeKey(clazz)
&& rangeKeyName.equals(reflector.getPrimaryRangeKeyName(clazz))) {
hasPrimaryRangeKeyCondition = true;
}
Collection<String> annotatedLSI = parsedIndexesInfo
.getLsiNamesByIndexRangeKey(rangeKeyName);
if (annotatedLSI != null) {
annotatedLSIsOnRangeKey.addAll(annotatedLSI);
}
Collection<String> annotatedGSI = parsedIndexesInfo
.getGsiNamesByIndexRangeKey(rangeKeyName);
if (annotatedGSI != null) {
annotatedGSIsOnRangeKey.addAll(annotatedGSI);
}
}
if (!hasPrimaryRangeKeyCondition
&& annotatedLSIsOnRangeKey.isEmpty()
&& annotatedGSIsOnRangeKey.isEmpty()) {
throw new DynamoDBMappingException(
"The query contains a condition on a range key ("
+
rangeKeyNameForThisQuery
+ ") "
+
"that is not annotated with either @DynamoDBRangeKey or @DynamoDBIndexRangeKey.");
}
}
final boolean userProvidedLSIWithRangeKeyCondition = (userProvidedIndexName != null)
&& (annotatedLSIsOnRangeKey.contains(userProvidedIndexName));
final boolean hashOnlyLSIQuery = (userProvidedIndexName != null)
&& (!hasRangeKeyCondition)
&& parsedIndexesInfo.getAllLsiNames().contains(userProvidedIndexName);
final boolean userProvidedLSI = userProvidedLSIWithRangeKeyCondition || hashOnlyLSIQuery;
final boolean userProvidedGSIWithRangeKeyCondition = (userProvidedIndexName != null)
&& (annotatedGSIsOnRangeKey.contains(userProvidedIndexName));
final boolean hashOnlyGSIQuery = (userProvidedIndexName != null)
&& (!hasRangeKeyCondition)
&& parsedIndexesInfo.getAllGsiNames().contains(userProvidedIndexName);
final boolean userProvidedGSI = userProvidedGSIWithRangeKeyCondition || hashOnlyGSIQuery;
if (userProvidedLSI && userProvidedGSI) {
throw new DynamoDBMappingException(
"Invalid query: " +
"Index \"" + userProvidedIndexName + "\" " +
"is annotateded as both a LSI and a GSI for attribute.");
}
// Hash key conditions
for (String hashKeyName : hashKeyConditions.keySet()) {
if (hashKeyName.equals(primaryHashKeyName)) {
hasPrimaryHashKeyCondition = true;
}
Collection<String> annotatedGSINames = parsedIndexesInfo
.getGsiNamesByIndexHashKey(hashKeyName);
annotatedGSIsOnHashKeys.put(hashKeyName,
annotatedGSINames == null ? new HashSet<String>() : new HashSet<String>(
annotatedGSINames));
// Additional validation if the user provided an index name.
if (userProvidedIndexName != null) {
boolean foundHashKeyConditionValidWithUserProvidedIndex = false;
if (userProvidedLSI && hashKeyName.equals(primaryHashKeyName)) {
// found an applicable hash key condition (primary hash +
// LSI range)
foundHashKeyConditionValidWithUserProvidedIndex = true;
} else if (userProvidedGSI &&
annotatedGSINames != null
&& annotatedGSINames.contains(userProvidedIndexName)) {
// found an applicable hash key condition (GSI hash + range)
foundHashKeyConditionValidWithUserProvidedIndex = true;
}
if (foundHashKeyConditionValidWithUserProvidedIndex) {
if (hashKeyNameForThisQuery != null) {
throw new IllegalArgumentException(
"Ambiguous query expression: More than one hash key EQ conditions ("
+
hashKeyNameForThisQuery + ", " + hashKeyName +
") are applicable to the specified index ("
+ userProvidedIndexName + "). " +
"Please provide only one of them in the query expression.");
} else {
// found an applicable hash key condition
hashKeyNameForThisQuery = hashKeyName;
}
}
}
}
// Collate all the key conditions
Map<String, Condition> keyConditions = new HashMap<String, Condition>();
// With user-provided index name
if (userProvidedIndexName != null) {
if (hasRangeKeyCondition
&& (!userProvidedLSI)
&& (!userProvidedGSI)) {
throw new IllegalArgumentException(
"Illegal query expression: No range key condition is applicable to the specified index ("
+ userProvidedIndexName + "). ");
}
if (hashKeyNameForThisQuery == null) {
throw new IllegalArgumentException(
"Illegal query expression: No hash key condition is applicable to the specified index ("
+ userProvidedIndexName + "). ");
}
keyConditions.put(hashKeyNameForThisQuery,
hashKeyConditions.get(hashKeyNameForThisQuery));
if (hasRangeKeyCondition) {
keyConditions.putAll(rangeKeyConditions);
}
}
// Infer the index name by finding the index shared by both hash and
// range key annotations.
else {
if (hasRangeKeyCondition) {
String inferredIndexName = null;
hashKeyNameForThisQuery = null;
if (hasPrimaryHashKeyCondition && hasPrimaryRangeKeyCondition) {
// Found valid query: primary hash + range key conditions
hashKeyNameForThisQuery = primaryHashKeyName;
} else {
// Intersect the set of all the indexes applicable to the
// range key
// with the set of indexes applicable to each hash key
// condition.
for (String hashKeyName : annotatedGSIsOnHashKeys.keySet()) {
boolean foundValidQueryExpressionWithInferredIndex = false;
String indexNameInferredByThisHashKey = null;
if (hashKeyName.equals(primaryHashKeyName)) {
if (annotatedLSIsOnRangeKey.size() == 1) {
// Found valid query (Primary hash + LSI range
// conditions)
foundValidQueryExpressionWithInferredIndex = true;
indexNameInferredByThisHashKey = annotatedLSIsOnRangeKey.iterator()
.next();
}
}
Set<String> annotatedGSIsOnHashKey = annotatedGSIsOnHashKeys
.get(hashKeyName);
// We don't need the data in annotatedGSIsOnHashKeys
// afterwards,
// so it's safe to do the intersection in-place.
annotatedGSIsOnHashKey.retainAll(annotatedGSIsOnRangeKey);
if (annotatedGSIsOnHashKey.size() == 1) {
// Found valid query (Hash + range conditions on a
// GSI)
if (foundValidQueryExpressionWithInferredIndex) {
hashKeyNameForThisQuery = hashKeyName;
inferredIndexName = indexNameInferredByThisHashKey;
}
foundValidQueryExpressionWithInferredIndex = true;
indexNameInferredByThisHashKey = annotatedGSIsOnHashKey.iterator()
.next();
}
if (foundValidQueryExpressionWithInferredIndex) {
if (hashKeyNameForThisQuery != null) {
throw new IllegalArgumentException(
"Ambiguous query expression: Found multiple valid queries: "
+
"(Hash: \"" + hashKeyNameForThisQuery
+ "\", Range: \"" + rangeKeyNameForThisQuery
+ "\", Index: \"" + inferredIndexName + "\") and " +
"(Hash: \"" + hashKeyName + "\", Range: \""
+ rangeKeyNameForThisQuery + "\", Index: \""
+ indexNameInferredByThisHashKey + "\").");
} else {
hashKeyNameForThisQuery = hashKeyName;
inferredIndexName = indexNameInferredByThisHashKey;
}
}
}
}
if (hashKeyNameForThisQuery != null) {
keyConditions.put(hashKeyNameForThisQuery,
hashKeyConditions.get(hashKeyNameForThisQuery));
keyConditions.putAll(rangeKeyConditions);
queryRequest.setIndexName(inferredIndexName);
} else {
throw new IllegalArgumentException(
"Illegal query expression: Cannot infer the index name from the query expression.");
}
} else {
// No range key condition is specified.
if (hashKeyConditions.size() > 1) {
if (hasPrimaryHashKeyCondition) {
keyConditions.put(primaryHashKeyName,
hashKeyConditions.get(primaryHashKeyName));
} else {
throw new IllegalArgumentException(
"Ambiguous query expression: More than one index hash key EQ conditions ("
+
hashKeyConditions.keySet()
+
") are applicable to the query. "
+
"Please provide only one of them in the query expression, or specify the appropriate index name.");
}
} else {
// Only one hash key condition
String hashKeyName = annotatedGSIsOnHashKeys.keySet().iterator().next();
if (!hasPrimaryHashKeyCondition) {
if (annotatedGSIsOnHashKeys.get(hashKeyName).size() == 1) {
// Set the index if the index hash key is only
// annotated with one GSI.
queryRequest.setIndexName(annotatedGSIsOnHashKeys.get(hashKeyName)
.iterator().next());
} else if (annotatedGSIsOnHashKeys.get(hashKeyName).size() > 1) {
throw new IllegalArgumentException(
"Ambiguous query expression: More than one GSIs (" +
annotatedGSIsOnHashKeys.get(hashKeyName) +
") are applicable to the query. " +
"Please specify one of them in your query expression.");
} else {
throw new IllegalArgumentException(
"Illegal query expression: No GSI is found in the @DynamoDBIndexHashKey annotation for attribute "
+
"\"" + hashKeyName + "\".");
}
}
keyConditions.putAll(hashKeyConditions);
}
}
}
queryRequest.setKeyConditions(keyConditions);
}
private <T> AttributeTransformer.Parameters<T> toParameters(
final Map<String, AttributeValue> attributeValues,
final Class<T> modelClass,
final String tableName,
final DynamoDBMapperConfig mapperConfig) {
return toParameters(attributeValues, false, modelClass, tableName, mapperConfig);
}
private <T> AttributeTransformer.Parameters<T> toParameters(
final Map<String, AttributeValue> attributeValues,
final boolean partialUpdate,
final Class<T> modelClass,
final String tableName,
final DynamoDBMapperConfig mapperConfig) {
return new TransformerParameters<T>(
reflector,
attributeValues,
partialUpdate,
modelClass,
mapperConfig,
tableName);
}
final <T> List<AttributeTransformer.Parameters<T>> toParameters(
final List<Map<String, AttributeValue>> attributeValues,
final Class<T> modelClass,
final String tableName,
final DynamoDBMapperConfig mapperConfig
) {
List<AttributeTransformer.Parameters<T>> rval =
new ArrayList<AttributeTransformer.Parameters<T>>(
attributeValues.size());
for (Map<String, AttributeValue> item : attributeValues) {
rval.add(toParameters(item, modelClass, tableName, mapperConfig));
}
return rval;
}
/**
* The one true implementation of AttributeTransformer.Parameters.
*/
private static class TransformerParameters<T>
implements AttributeTransformer.Parameters<T> {
private final DynamoDBReflector reflector;
private final Map<String, AttributeValue> attributeValues;
private final boolean partialUpdate;
private final Class<T> modelClass;
private final DynamoDBMapperConfig mapperConfig;
private final String tableName;
private String hashKeyName;
private String rangeKeyName;
public TransformerParameters(
final DynamoDBReflector reflector,
final Map<String, AttributeValue> attributeValues,
final boolean partialUpdate,
final Class<T> modelClass,
final DynamoDBMapperConfig mapperConfig,
final String tableName) {
this.reflector = reflector;
this.attributeValues =
Collections.unmodifiableMap(attributeValues);
this.partialUpdate = partialUpdate;
this.modelClass = modelClass;
this.mapperConfig = mapperConfig;
this.tableName = tableName;
}
@Override
public Map<String, AttributeValue> getAttributeValues() {
return attributeValues;
}
@Override
public boolean isPartialUpdate() {
return partialUpdate;
}
@Override
public Class<T> getModelClass() {
return modelClass;
}
@Override
public DynamoDBMapperConfig getMapperConfig() {
return mapperConfig;
}
@Override
public String getTableName() {
return tableName;
}
@Override
public String getHashKeyName() {
if (hashKeyName == null) {
Method hashKeyGetter = reflector.getPrimaryHashKeyGetter(modelClass);
hashKeyName = reflector.getAttributeName(hashKeyGetter);
}
return hashKeyName;
}
@Override
public String getRangeKeyName() {
if (rangeKeyName == null) {
Method rangeKeyGetter =
reflector.getPrimaryRangeKeyGetter(modelClass);
if (rangeKeyGetter == null) {
rangeKeyName = NO_RANGE_KEY;
} else {
rangeKeyName = reflector.getAttributeName(rangeKeyGetter);
}
}
if (rangeKeyName == NO_RANGE_KEY) {
return null;
}
return rangeKeyName;
}
}
private Map<String, AttributeValue> untransformAttributes(
final AttributeTransformer.Parameters<?> parameters
) {
if (transformer != null) {
return transformer.untransform(parameters);
} else {
return parameters.getAttributeValues();
}
}
private Map<String, AttributeValue> transformAttributes(
final AttributeTransformer.Parameters<?> parameters) {
if (transformer != null) {
return transformer.transform(parameters);
} else {
return parameters.getAttributeValues();
}
}
Map<String, AttributeValueUpdate> transformAttributeUpdates(
final Class<?> clazz,
final String tableName,
final Map<String, AttributeValue> keys,
final Map<String, AttributeValueUpdate> updateValues,
final DynamoDBMapperConfig config
) {
Map<String, AttributeValue> item = convertToItem(updateValues);
HashSet<String> keysAdded = new HashSet<String>();
for (Map.Entry<String, AttributeValue> e : keys.entrySet()) {
if (!item.containsKey(e.getKey())) {
keysAdded.add(e.getKey());
item.put(e.getKey(), e.getValue());
}
}
AttributeTransformer.Parameters<?> parameters =
toParameters(item, true, clazz, tableName, config);
String hashKey = parameters.getHashKeyName();
if (!item.containsKey(hashKey)) {
item.put(hashKey, keys.get(hashKey));
}
item = transformAttributes(parameters);
for (Map.Entry<String, AttributeValue> entry : item.entrySet()) {
if (keysAdded.contains(entry.getKey())) {
// This was added in for context before calling
// transformAttributes, but isn't actually being changed.
continue;
}
AttributeValueUpdate update = updateValues.get(entry.getKey());
if (update != null) {
update.getValue()
.withB(entry.getValue().getB())
.withBS(entry.getValue().getBS())
.withN(entry.getValue().getN())
.withNS(entry.getValue().getNS())
.withS(entry.getValue().getS())
.withSS(entry.getValue().getSS());
} else {
updateValues.put(entry.getKey(),
new AttributeValueUpdate(entry.getValue(),
"PUT"));
}
}
return updateValues;
}
ItemConverter getConverter(DynamoDBMapperConfig config) {
ConversionSchema schema = config.getConversionSchema();
ConversionSchema.Dependencies params = new ConversionSchema.Dependencies()
.with(DynamoDBReflector.class, reflector)
.with(S3ClientCache.class, s3cc);
return schema.getConverter(params);
}
private void pauseExponentially(int retries) {
if (retries == 0) {
return;
}
Random random = new Random();
long delay = 0;
long scaleFactor = 500 + random.nextInt(100);
delay = (long) (Math.pow(2, retries) * scaleFactor);
delay = Math.min(delay, MAX_BACKOFF_IN_MILLISECONDS);
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new AmazonClientException(e.getMessage(), e);
}
}
/**
* Returns a new map object that merges the two sets of expected value
* conditions (user-specified or imposed by the internal implementation of
* DynamoDBMapper). Internal assertion on an attribute will be overridden by
* any user-specified condition on the same attribute.
* <p>
* Exception is thrown if the two sets of conditions cannot be combined
* together.
*/
static Map<String, ExpectedAttributeValue> mergeExpectedAttributeValueConditions(
Map<String, ExpectedAttributeValue> internalAssertions,
Map<String, ExpectedAttributeValue> userProvidedConditions,
String userProvidedConditionOperator) {
// If any of the condition map is null, simply return a copy of the
// other one.
if ((internalAssertions == null || internalAssertions.isEmpty())
&& (userProvidedConditions == null || userProvidedConditions.isEmpty())) {
return null;
} else if (internalAssertions == null) {
return new HashMap<String, ExpectedAttributeValue>(userProvidedConditions);
} else if (userProvidedConditions == null) {
return new HashMap<String, ExpectedAttributeValue>(internalAssertions);
}
// Start from a copy of the internal conditions
Map<String, ExpectedAttributeValue> mergedExpectedValues =
new HashMap<String, ExpectedAttributeValue>(internalAssertions);
// Remove internal conditions that are going to be overlaid by
// user-provided ones.
for (String attrName : userProvidedConditions.keySet()) {
mergedExpectedValues.remove(attrName);
}
// All the generated internal conditions must be joined by AND.
// Throw an exception if the user specifies an OR operator, and that the
// internal conditions are not totally overlaid by the user-provided
// ones.
if (ConditionalOperator.OR.toString().equals(userProvidedConditionOperator)
&& !mergedExpectedValues.isEmpty()) {
throw new IllegalArgumentException(
"Unable to assert the value of the fields "
+ mergedExpectedValues.keySet()
+ ", since the expected value conditions cannot be combined "
+ "with user-specified conditions joined by \"OR\". You can use SaveBehavior.CLOBBER to "
+ "skip the assertion on these fields.");
}
mergedExpectedValues.putAll(userProvidedConditions);
return mergedExpectedValues;
}
static <X extends AmazonWebServiceRequest> X applyUserAgent(X request) {
request.getRequestClientOptions().appendUserAgent(USER_AGENT);
return request;
}
static <X extends AmazonWebServiceRequest> X applyBatchOperationUserAgent(X request) {
request.getRequestClientOptions().appendUserAgent(USER_AGENT_BATCH_OPERATION);
return request;
}
/**
* The return type of batchWrite, batchDelete and batchSave. It contains the
* information about the unprocessed items and the exception causing the
* failure.
*/
public static class FailedBatch {
private Map<String, java.util.List<WriteRequest>> unprocessedItems;
private Exception exception;
public void setUnprocessedItems(Map<String, java.util.List<WriteRequest>> unprocessedItems) {
this.unprocessedItems = unprocessedItems;
}
public Map<String, java.util.List<WriteRequest>> getUnprocessedItems() {
return unprocessedItems;
}
public void setException(Exception excetpion) {
this.exception = excetpion;
}
public Exception getException() {
return exception;
}
}
/**
* Returns the underlying {@link S3ClientCache} for accessing S3.
*/
public S3ClientCache getS3ClientCache() {
return s3cc;
}
/**
* Creates an S3Link with the specified bucket name and key using the
* default S3 region. This method requires the mapper to have been
* initialized with the necessary credentials for accessing S3.
*
* @throws IllegalStateException if the mapper has not been constructed with
* the necessary S3 AWS credentials.
*/
public S3Link createS3Link(String bucketName, String key) {
return createS3Link(null, bucketName, key);
}
/**
* Creates an S3Link with the specified region, bucket name and key. This
* method requires the mapper to have been initialized with the necessary
* credentials for accessing S3.
*
* @throws IllegalStateException if the mapper has not been constructed with
* the necessary S3 AWS credentials.
*/
public S3Link createS3Link(Region s3region, String bucketName, String key) {
if (s3cc == null) {
throw new IllegalStateException(
"Mapper must be constructed with S3 AWS Credentials to create S3Link");
}
return new S3Link(s3cc, s3region, bucketName, key);
}
/**
* Parse the given POJO class and return the CreateTableRequest for the
* DynamoDB table it represents. Note that the returned request does not
* include the required ProvisionedThroughput parameters for the primary
* table and the GSIs, and that all secondary indexes are initialized with
* the default projection type - KEY_ONLY.
*/
public CreateTableRequest generateCreateTableRequest(Class<?> clazz) {
ItemConverter converter = getConverter(config);
return schemaParser.parseTablePojoToCreateTableRequest(
clazz, config, reflector, converter);
}
}