StreamsAdapterDemoHelper.java

/*
* Copyright 2014-2015 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.
* A copy of the License is located at
*
*  http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. 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.codesamples.gsg;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
import com.amazonaws.services.dynamodbv2.model.AttributeAction;
import com.amazonaws.services.dynamodbv2.model.AttributeDefinition;
import com.amazonaws.services.dynamodbv2.model.AttributeValue;
import com.amazonaws.services.dynamodbv2.model.AttributeValueUpdate;
import com.amazonaws.services.dynamodbv2.model.CreateTableRequest;
import com.amazonaws.services.dynamodbv2.model.CreateTableResult;
import com.amazonaws.services.dynamodbv2.model.DeleteItemRequest;
import com.amazonaws.services.dynamodbv2.model.DescribeTableRequest;
import com.amazonaws.services.dynamodbv2.model.DescribeTableResult;
import com.amazonaws.services.dynamodbv2.model.KeySchemaElement;
import com.amazonaws.services.dynamodbv2.model.KeyType;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
import com.amazonaws.services.dynamodbv2.model.PutItemRequest;
import com.amazonaws.services.dynamodbv2.model.ResourceInUseException;
import com.amazonaws.services.dynamodbv2.model.ScanRequest;
import com.amazonaws.services.dynamodbv2.model.ScanResult;
import com.amazonaws.services.dynamodbv2.model.StreamSpecification;
import com.amazonaws.services.dynamodbv2.model.StreamViewType;
import com.amazonaws.services.dynamodbv2.model.UpdateItemRequest;


public class StreamsAdapterDemoHelper {

    /**
     * @return StreamArn
     */
    public static String createTable(AmazonDynamoDBClient client, String tableName) {
        java.util.List<AttributeDefinition> attributeDefinitions = new ArrayList<AttributeDefinition>();
        attributeDefinitions.add(new AttributeDefinition().withAttributeName("Id").withAttributeType("N"));

        java.util.List<KeySchemaElement> keySchema = new ArrayList<KeySchemaElement>();
        keySchema.add(new KeySchemaElement().withAttributeName("Id").withKeyType(KeyType.HASH));

        ProvisionedThroughput provisionedThroughput = new ProvisionedThroughput()
            .withReadCapacityUnits(2L).withWriteCapacityUnits(2L);

        StreamSpecification streamSpecification = new StreamSpecification();
        streamSpecification.setStreamEnabled(true);
        streamSpecification.setStreamViewType(StreamViewType.NEW_IMAGE);
        CreateTableRequest createTableRequest = new CreateTableRequest()
            .withTableName(tableName)
            .withAttributeDefinitions(attributeDefinitions)
            .withKeySchema(keySchema)
            .withProvisionedThroughput(provisionedThroughput)
            .withStreamSpecification(streamSpecification);

        try {
            System.out.println("Creating table " + tableName);
            CreateTableResult result = client.createTable(createTableRequest);
            return result.getTableDescription().getLatestStreamArn();
        } catch(ResourceInUseException e) {
            System.out.println("Table already exists.");
            return describeTable(client, tableName).getTable().getLatestStreamArn();
        }
    }

    public static DescribeTableResult describeTable(AmazonDynamoDBClient client, String tableName) {
        return client.describeTable(new DescribeTableRequest().withTableName(tableName));
    }

    public static ScanResult scanTable(AmazonDynamoDBClient client, String tableName) {
        return client.scan(new ScanRequest().withTableName(tableName));
    }

    public static void putItem(AmazonDynamoDBClient client, String tableName, String id, String val) {
        java.util.Map<String, AttributeValue> item = new HashMap<String, AttributeValue>();
        item.put("Id", new AttributeValue().withN(id));
        item.put("attribute-1", new AttributeValue().withS(val));

        PutItemRequest putItemRequest = new PutItemRequest()
            .withTableName(tableName)
            .withItem(item);
        client.putItem(putItemRequest);
    }

    public static void putItem(AmazonDynamoDBClient client, String tableName, java.util.Map<String, AttributeValue> items) {
        PutItemRequest putItemRequest = new PutItemRequest()
            .withTableName(tableName)
            .withItem(items);
        client.putItem(putItemRequest);
    }

    public static void updateItem(AmazonDynamoDBClient client, String tableName, String id, String val) {
        java.util.Map<String, AttributeValue> key = new HashMap<String, AttributeValue>();
        key.put("Id", new AttributeValue().withN(id));

        Map<String, AttributeValueUpdate> attributeUpdates = new HashMap<String, AttributeValueUpdate>();
        AttributeValueUpdate update = new AttributeValueUpdate()
            .withAction(AttributeAction.PUT)
            .withValue(new AttributeValue().withS(val));
        attributeUpdates.put("attribute-2", update);

        UpdateItemRequest updateItemRequest = new UpdateItemRequest()
            .withTableName(tableName)
            .withKey(key)
            .withAttributeUpdates(attributeUpdates);
        client.updateItem(updateItemRequest);
    }

    public static void deleteItem(AmazonDynamoDBClient client, String tableName, String id) {
        java.util.Map<String, AttributeValue> key = new HashMap<String, AttributeValue>();
        key.put("Id", new AttributeValue().withN(id));

        DeleteItemRequest deleteItemRequest = new DeleteItemRequest()
            .withTableName(tableName)
            .withKey(key);
        client.deleteItem(deleteItemRequest);
    }

}