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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.olingo.odata2.core.ep.consumer;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.olingo.odata2.api.edm.Edm;
import org.apache.olingo.odata2.api.edm.EdmEntitySetInfo;
import org.apache.olingo.odata2.api.edm.EdmException;
import org.apache.olingo.odata2.api.edm.provider.EntityContainerInfo;
import org.apache.olingo.odata2.api.edm.provider.EntitySet;
import org.apache.olingo.odata2.api.ep.EntityProviderException;
import org.apache.olingo.odata2.core.edm.provider.EdmEntitySetInfoImplProv;
import org.apache.olingo.odata2.core.ep.util.FormatJson;
import org.apache.olingo.odata2.core.servicedocument.ServiceDocumentImpl;
import com.google.gson.stream.JsonReader;
/**
* Reads the OData service document (JSON).
*
*/
public class JsonServiceDocumentConsumer {
private static final String DEFAULT_CHARSET = "UTF-8";
List<EdmEntitySetInfo> entitySets = new ArrayList<EdmEntitySetInfo>();
private String currentHandledObjectName;
public ServiceDocumentImpl parseJson(final InputStream in) throws EntityProviderException {
return readServiceDocument(createJsonReader(in));
}
private ServiceDocumentImpl readServiceDocument(final JsonReader reader) throws EntityProviderException {
try {
reader.beginObject();
currentHandledObjectName = reader.nextName();
if (FormatJson.D.equals(currentHandledObjectName)) {
reader.beginObject();
readContent(reader);
reader.endObject();
}
reader.endObject();
reader.peek();
reader.close();
} 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);
} catch (final EdmException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass()
.getSimpleName()), e);
}
return new ServiceDocumentImpl().setEntitySetsInfo(entitySets);
}
private void readContent(final JsonReader reader) throws IOException, EdmException, EntityProviderException {
currentHandledObjectName = reader.nextName();
if (FormatJson.ENTITY_SETS.equals(currentHandledObjectName)) {
reader.beginArray();
readEntitySets(reader);
reader.endArray();
}
}
private void readEntitySets(final JsonReader reader) throws IOException, EntityProviderException, EdmException {
while (reader.hasNext()) {
currentHandledObjectName = reader.nextString();
if (currentHandledObjectName != null) {
// Looking for the last dot: "\\.(?=[^.]+$)"
String[] names = currentHandledObjectName.split("\\" + Edm.DELIMITER + "(?=[^" + Edm.DELIMITER + "]+$)");
if (names.length == 1) {
EntitySet entitySet = new EntitySet().setName(names[0]);
EntityContainerInfo container = new EntityContainerInfo().setDefaultEntityContainer(true);
EdmEntitySetInfo entitySetInfo = new EdmEntitySetInfoImplProv(entitySet, container);
entitySets.add(entitySetInfo);
} else {
EntitySet entitySet = new EntitySet().setName(names[1]);
EntityContainerInfo container = new EntityContainerInfo().setName(names[0]).setDefaultEntityContainer(false);
EdmEntitySetInfo entitySetInfo = new EdmEntitySetInfoImplProv(entitySet, container);
entitySets.add(entitySetInfo);
}
}
}
}
private JsonReader createJsonReader(final InputStream in) throws EntityProviderException {
if (in == null) {
throw new EntityProviderException(EntityProviderException.INVALID_STATE
.addContent(("Got not supported NULL object as content to de-serialize.")));
}
InputStreamReader isReader;
try {
isReader = new InputStreamReader(in, DEFAULT_CHARSET);
} catch (final UnsupportedEncodingException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass()
.getSimpleName()), e);
}
return new JsonReader(isReader);
}
}