| /******************************************************************************* |
| * 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.producer; |
| |
| import java.io.IOException; |
| import java.io.Writer; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.apache.olingo.odata2.api.commons.InlineCount; |
| import org.apache.olingo.odata2.api.ep.EntityProviderException; |
| import org.apache.olingo.odata2.api.ep.EntityProviderWriteProperties; |
| import org.apache.olingo.odata2.api.ep.callback.TombstoneCallback; |
| import org.apache.olingo.odata2.api.ep.callback.TombstoneCallbackResult; |
| import org.apache.olingo.odata2.core.ep.EntityProviderProducerException; |
| import org.apache.olingo.odata2.core.ep.aggregator.EntityInfoAggregator; |
| import org.apache.olingo.odata2.core.ep.util.FormatJson; |
| import org.apache.olingo.odata2.core.ep.util.JsonStreamWriter; |
| |
| /** |
| * Producer for writing an entity collection (a feed) in JSON. |
| * |
| */ |
| public class JsonFeedEntityProducer { |
| |
| private final EntityProviderWriteProperties properties; |
| |
| public JsonFeedEntityProducer(final EntityProviderWriteProperties properties) throws EntityProviderException { |
| this.properties = properties == null ? EntityProviderWriteProperties.serviceRoot(null).build() : properties; |
| } |
| |
| public void appendAsObject(final Writer writer, final EntityInfoAggregator entityInfo, |
| final List<Map<String, Object>> data, |
| final boolean isRootElement) throws EntityProviderException { |
| JsonStreamWriter jsonStreamWriter = new JsonStreamWriter(writer); |
| |
| TombstoneCallback callback = getTombstoneCallback(); |
| |
| try { |
| jsonStreamWriter.beginObject(); |
| |
| if (isRootElement) { |
| jsonStreamWriter.name(FormatJson.D) |
| .beginObject(); |
| } |
| |
| if (properties.getInlineCountType() == InlineCount.ALLPAGES) { |
| final int inlineCount = properties.getInlineCount() == null ? 0 : properties.getInlineCount(); |
| jsonStreamWriter.namedStringValueRaw(FormatJson.COUNT, String.valueOf(inlineCount)).separator(); |
| } |
| |
| jsonStreamWriter.name(FormatJson.RESULTS) |
| .beginArray(); |
| |
| appendEntries(writer, entityInfo, data, jsonStreamWriter); |
| |
| if (callback != null) { |
| appendDeletedEntries(writer, entityInfo, data, callback); |
| } |
| |
| jsonStreamWriter.endArray(); |
| |
| appendNextLink(jsonStreamWriter); |
| appendDeltaLink(callback, jsonStreamWriter); |
| |
| if (isRootElement) { |
| jsonStreamWriter.endObject(); |
| } |
| |
| jsonStreamWriter.endObject(); |
| } catch (final IOException e) { |
| throw new EntityProviderProducerException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass() |
| .getSimpleName()), e); |
| } |
| } |
| |
| public void appendAsArray(final Writer writer, final EntityInfoAggregator entityInfo, |
| final List<Map<String, Object>> data) throws EntityProviderException { |
| JsonStreamWriter jsonStreamWriter = new JsonStreamWriter(writer); |
| try { |
| jsonStreamWriter.beginArray(); |
| appendEntries(writer, entityInfo, data, jsonStreamWriter); |
| jsonStreamWriter.endArray(); |
| } catch (final IOException e) { |
| throw new EntityProviderProducerException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass() |
| .getSimpleName()), e); |
| } |
| } |
| |
| private void appendDeletedEntries(final Writer writer, final EntityInfoAggregator entityInfo, |
| final List<Map<String, Object>> data, TombstoneCallback callback) throws EntityProviderException { |
| JsonDeletedEntryEntityProducer deletedEntryProducer = new JsonDeletedEntryEntityProducer(properties); |
| TombstoneCallbackResult callbackResult = callback.getTombstoneCallbackResult(); |
| List<Map<String, Object>> deletedEntries = callbackResult.getDeletedEntriesData(); |
| if (deletedEntries != null) { |
| deletedEntryProducer.append(writer, entityInfo, deletedEntries, data.isEmpty()); |
| } |
| } |
| |
| private void appendEntries(final Writer writer, final EntityInfoAggregator entityInfo, |
| final List<Map<String, Object>> data, JsonStreamWriter jsonStreamWriter) throws EntityProviderException, |
| IOException { |
| JsonEntryEntityProducer entryProducer = new JsonEntryEntityProducer(properties); |
| boolean first = true; |
| for (final Map<String, Object> entryData : data) { |
| if (first) { |
| first = false; |
| } else { |
| jsonStreamWriter.separator(); |
| } |
| entryProducer.append(writer, entityInfo, entryData, false); |
| } |
| } |
| |
| private TombstoneCallback getTombstoneCallback() { |
| if (properties.getCallbacks() != null |
| && properties.getCallbacks().containsKey(TombstoneCallback.CALLBACK_KEY_TOMBSTONE)) { |
| TombstoneCallback callback = |
| (TombstoneCallback) properties.getCallbacks().get(TombstoneCallback.CALLBACK_KEY_TOMBSTONE); |
| return callback; |
| } else { |
| return null; |
| } |
| } |
| |
| private void appendNextLink(final JsonStreamWriter jsonStreamWriter) throws IOException { |
| // Write "next" link. |
| // To be compatible with other implementations out there, the link is |
| // written directly after "__next" and not as "{"uri":"next link"}", |
| // deviating from the OData 2.0 specification. |
| if (properties.getNextLink() != null) { |
| jsonStreamWriter.separator() |
| .namedStringValue(FormatJson.NEXT, properties.getNextLink()); |
| } |
| } |
| |
| private void appendDeltaLink(final TombstoneCallback callback, final JsonStreamWriter jsonStreamWriter) |
| throws IOException { |
| if (callback != null) { |
| TombstoneCallbackResult callbackResult = callback.getTombstoneCallbackResult(); |
| |
| String deltaLink = callbackResult.getDeltaLink(); |
| if (deltaLink != null) { |
| jsonStreamWriter.separator().namedStringValue(FormatJson.DELTA, deltaLink); |
| } |
| } |
| } |
| } |