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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.util.ArrayList;
import java.util.List;
import org.apache.olingo.odata2.api.edm.EdmException;
import org.apache.olingo.odata2.api.ep.EntityProviderException;
import org.apache.olingo.odata2.api.ep.EntityProviderReadProperties;
import org.apache.olingo.odata2.api.ep.entry.DeletedEntryMetadata;
import org.apache.olingo.odata2.api.ep.entry.ODataEntry;
import org.apache.olingo.odata2.api.ep.feed.ODataDeltaFeed;
import org.apache.olingo.odata2.api.ep.feed.ODataFeed;
import org.apache.olingo.odata2.core.ep.aggregator.EntityInfoAggregator;
import org.apache.olingo.odata2.core.ep.feed.FeedMetadataImpl;
import org.apache.olingo.odata2.core.ep.feed.JsonFeedEntry;
import org.apache.olingo.odata2.core.ep.feed.ODataDeltaFeedImpl;
import org.apache.olingo.odata2.core.ep.util.FormatJson;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
/**
*
*/
public class JsonFeedConsumer {
private JsonReader reader;
private EntityInfoAggregator eia;
private EntityProviderReadProperties readProperties;
private List<DeletedEntryMetadata> deletedEntries = new ArrayList<DeletedEntryMetadata>();
private List<ODataEntry> entries = new ArrayList<ODataEntry>();
private FeedMetadataImpl feedMetadata = new FeedMetadataImpl();
private boolean resultsArrayPresent = false;
public JsonFeedConsumer(final JsonReader reader, final EntityInfoAggregator eia,
final EntityProviderReadProperties readProperties) {
this.reader = reader;
this.eia = eia;
this.readProperties = readProperties;
}
public ODataDeltaFeed readFeedStandalone() throws EntityProviderException {
try {
readFeed();
if (reader.peek() != JsonToken.END_DOCUMENT) {
throw new EntityProviderException(EntityProviderException.END_DOCUMENT_EXPECTED.addContent(reader.peek()
.toString()));
}
} catch (IOException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass()
.getSimpleName()), e);
} catch (EdmException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass()
.getSimpleName()), e);
} catch (IllegalStateException e) {
throw new EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass()
.getSimpleName()), e);
}
return new ODataDeltaFeedImpl(entries, feedMetadata, deletedEntries);
}
private void readFeed() throws IOException, EdmException, EntityProviderException {
JsonToken peek = reader.peek();
if (peek == JsonToken.BEGIN_ARRAY) {
readArrayContent();
} else {
reader.beginObject();
final String nextName = reader.nextName();
if (FormatJson.D.equals(nextName)) {
if (reader.peek() == JsonToken.BEGIN_ARRAY) {
readArrayContent();
} else {
reader.beginObject();
readFeedContent();
reader.endObject();
}
} else {
handleName(nextName);
readFeedContent();
}
reader.endObject();
}
}
private void readFeedContent() throws IOException, EdmException, EntityProviderException {
while (reader.hasNext()) {
final String nextName = reader.nextName();
handleName(nextName);
}
if (!resultsArrayPresent) {
throw new EntityProviderException(EntityProviderException.MISSING_RESULTS_ARRAY);
}
}
private void handleName(final String nextName) throws IOException, EdmException, EntityProviderException {
if (FormatJson.RESULTS.equals(nextName)) {
resultsArrayPresent = true;
readArrayContent();
} else if (FormatJson.COUNT.equals(nextName)) {
readInlineCount(reader, feedMetadata);
} else if (FormatJson.NEXT.equals(nextName)) {
if (reader.peek() == JsonToken.STRING && feedMetadata.getNextLink() == null) {
String nextLink = reader.nextString();
feedMetadata.setNextLink(nextLink);
} else {
throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent(nextName).addContent(
"JsonFeed"));
}
} else if (FormatJson.DELTA.equals(nextName)) {
if (reader.peek() == JsonToken.STRING && feedMetadata.getDeltaLink() == null) {
String deltaLink = reader.nextString();
feedMetadata.setDeltaLink(deltaLink);
} else {
throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent(nextName).addContent(
"JsonFeed"));
}
} else {
throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent(nextName).addContent(
"JsonFeed"));
}
}
private void readArrayContent() throws IOException, EdmException, EntityProviderException {
reader.beginArray();
while (reader.hasNext()) {
final JsonFeedEntry entry = new JsonEntryConsumer(reader, eia, readProperties).readFeedEntry();
if (entry.isODataEntry()) {
entries.add(entry.getODataEntry());
} else {
deletedEntries.add(entry.getDeletedEntryMetadata());
}
}
reader.endArray();
}
protected static void readInlineCount(final JsonReader reader, final FeedMetadataImpl feedMetadata)
throws IOException, EntityProviderException {
if (reader.peek() == JsonToken.STRING && feedMetadata.getInlineCount() == null) {
int inlineCount;
try {
inlineCount = reader.nextInt();
} catch (final NumberFormatException e) {
throw new EntityProviderException(EntityProviderException.INLINECOUNT_INVALID.addContent(""), e);
}
if (inlineCount >= 0) {
feedMetadata.setInlineCount(inlineCount);
} else {
throw new EntityProviderException(EntityProviderException.INLINECOUNT_INVALID.addContent(inlineCount));
}
} else {
throw new EntityProviderException(EntityProviderException.INLINECOUNT_INVALID.addContent(reader.peek()));
}
}
protected ODataFeed readStartedInlineFeed(final String name) throws EdmException, EntityProviderException,
IOException {
// consume the already started content
handleName(name);
// consume the rest of the entry content
readFeedContent();
return new ODataDeltaFeedImpl(entries, feedMetadata);
}
protected ODataFeed readInlineFeedStandalone() throws EdmException, EntityProviderException, IOException {
readFeed();
return new ODataDeltaFeedImpl(entries, feedMetadata);
}
}