/*******************************************************************************
* Copyright 2013 SAP AG
*
* 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://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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.sap.core.odata.core.ep.consumer;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.sap.core.odata.api.edm.Edm;
import com.sap.core.odata.api.edm.EdmException;
import com.sap.core.odata.api.edm.EdmLiteralKind;
import com.sap.core.odata.api.edm.EdmProperty;
import com.sap.core.odata.api.edm.EdmSimpleType;
import com.sap.core.odata.api.edm.EdmSimpleTypeKind;
import com.sap.core.odata.api.ep.EntityProviderException;
import com.sap.core.odata.api.ep.EntityProviderReadProperties;
import com.sap.core.odata.core.ep.aggregator.EntityComplexPropertyInfo;
import com.sap.core.odata.core.ep.aggregator.EntityInfoAggregator;
import com.sap.core.odata.core.ep.aggregator.EntityPropertyInfo;
import com.sap.core.odata.core.ep.util.FormatJson;
/**
* @author SAP AG
*/
public class JsonPropertyConsumer {
public Map<String, Object> readPropertyStandalone(final JsonReader reader, final EdmProperty property, final EntityProviderReadProperties readProperties) throws EntityProviderException {
try {
EntityPropertyInfo entityPropertyInfo = EntityInfoAggregator.create(property);
Map<String, Object> typeMappings = readProperties == null ? null : readProperties.getTypeMappings();
Map<String, Object> result = new HashMap<String, Object>();
reader.beginObject();
String nextName = reader.nextName();
if (FormatJson.D.equals(nextName)) {
reader.beginObject();
nextName = reader.nextName();
handleName(reader, typeMappings, entityPropertyInfo, result, nextName);
reader.endObject();
} else {
handleName(reader, typeMappings, entityPropertyInfo, result, nextName);
}
reader.endObject();
if (reader.peek() != JsonToken.END_DOCUMENT) {
throw new EntityProviderException(EntityProviderException.END_DOCUMENT_EXPECTED.addContent(reader.peek().toString()));
}
return result;
} catch (final IOException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass().getSimpleName()), e);
} catch (final IllegalStateException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass().getSimpleName()), e);
}
}
private void handleName(final JsonReader reader, final Map<String, Object> typeMappings, final EntityPropertyInfo entityPropertyInfo, final Map<String, Object> result, final String nextName) throws EntityProviderException {
if (!entityPropertyInfo.getName().equals(nextName)) {
throw new EntityProviderException(EntityProviderException.ILLEGAL_ARGUMENT.addContent(nextName));
}
Object mapping = null;
if (typeMappings != null) {
mapping = typeMappings.get(nextName);
}
Object propertyValue = readPropertyValue(reader, entityPropertyInfo, mapping);
result.put(nextName, propertyValue);
}
protected Object readPropertyValue(final JsonReader reader, final EntityPropertyInfo entityPropertyInfo, final Object typeMapping) throws EntityProviderException {
try {
return entityPropertyInfo.isComplex() ?
readComplexProperty(reader, (EntityComplexPropertyInfo) entityPropertyInfo, typeMapping) :
readSimpleProperty(reader, entityPropertyInfo, typeMapping);
} catch (final EdmException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass().getSimpleName()), e);
} catch (final IOException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass().getSimpleName()), e);
}
}
private Object readSimpleProperty(final JsonReader reader, final EntityPropertyInfo entityPropertyInfo, final Object typeMapping) throws EdmException, EntityProviderException, IOException {
final EdmSimpleType type = (EdmSimpleType) entityPropertyInfo.getType();
Object value = null;
final JsonToken tokenType = reader.peek();
if (tokenType == JsonToken.NULL) {
reader.nextNull();
} else {
switch (EdmSimpleTypeKind.valueOf(type.getName())) {
case Boolean:
if (tokenType == JsonToken.BOOLEAN) {
value = reader.nextBoolean();
value = value.toString();
} else {
throw new EntityProviderException(EntityProviderException.INVALID_PROPERTY_VALUE.addContent(entityPropertyInfo.getName()));
}
break;
case Byte:
case SByte:
case Int16:
case Int32:
if (tokenType == JsonToken.NUMBER) {
value = reader.nextInt();
value = value.toString();
} else {
throw new EntityProviderException(EntityProviderException.INVALID_PROPERTY_VALUE.addContent(entityPropertyInfo.getName()));
}
break;
default:
if (tokenType == JsonToken.STRING) {
value = reader.nextString();
} else {
throw new EntityProviderException(EntityProviderException.INVALID_PROPERTY_VALUE.addContent(entityPropertyInfo.getName()));
}
break;
}
}
final Class<?> typeMappingClass = typeMapping == null ? type.getDefaultType() : (Class<?>) typeMapping;
return type.valueOfString((String) value, EdmLiteralKind.JSON, entityPropertyInfo.getFacets(), typeMappingClass);
}
@SuppressWarnings("unchecked")
private Object readComplexProperty(final JsonReader reader, final EntityComplexPropertyInfo complexPropertyInfo, final Object typeMapping) throws EdmException, EntityProviderException, IOException {
if (reader.peek().equals(JsonToken.NULL)) {
reader.nextNull();
if (complexPropertyInfo.isMandatory()) {
throw new EntityProviderException(EntityProviderException.INVALID_PROPERTY_VALUE.addContent(complexPropertyInfo.getName()));
}
return null;
}
reader.beginObject();
Map<String, Object> data = new HashMap<String, Object>();
Map<String, Object> mapping;
if (typeMapping != null) {
if (typeMapping instanceof Map) {
mapping = (Map<String, Object>) typeMapping;
} else {
throw new EntityProviderException(EntityProviderException.INVALID_MAPPING.addContent(complexPropertyInfo.getName()));
}
} else {
mapping = new HashMap<String, Object>();
}
while (reader.hasNext()) {
String childName = reader.nextName();
if (FormatJson.METADATA.equals(childName)) {
reader.beginObject();
childName = reader.nextName();
if (!FormatJson.TYPE.equals(childName)) {
throw new EntityProviderException(EntityProviderException.MISSING_ATTRIBUTE.addContent(FormatJson.TYPE).addContent(FormatJson.METADATA));
}
String actualTypeName = reader.nextString();
String expectedTypeName = complexPropertyInfo.getType().getNamespace() + Edm.DELIMITER + complexPropertyInfo.getType().getName();
if (!expectedTypeName.equals(actualTypeName)) {
throw new EntityProviderException(EntityProviderException.INVALID_ENTITYTYPE.addContent(expectedTypeName).addContent(actualTypeName));
}
reader.endObject();
} else {
EntityPropertyInfo childPropertyInfo = complexPropertyInfo.getPropertyInfo(childName);
if (childPropertyInfo == null) {
throw new EntityProviderException(EntityProviderException.INVALID_PROPERTY.addContent(childName));
}
Object childData = readPropertyValue(reader, childPropertyInfo, mapping.get(childName));
if (data.containsKey(childName)) {
throw new EntityProviderException(EntityProviderException.DOUBLE_PROPERTY.addContent(childName));
}
data.put(childName, childData);
}
}
reader.endObject();
return data;
}
}