| /******************************************************************************* |
| * 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.EdmEntitySet; |
| import org.apache.olingo.odata2.api.ep.EntityProviderException; |
| import org.apache.olingo.odata2.core.ep.feed.FeedMetadataImpl; |
| import org.apache.olingo.odata2.core.ep.util.FormatJson; |
| |
| import com.google.gson.stream.JsonReader; |
| import com.google.gson.stream.JsonToken; |
| |
| /** |
| * |
| */ |
| public class JsonLinkConsumer { |
| |
| /** |
| * Reads single link with format <code>{"d":{"uri":"http://somelink"}}</code> |
| * or <code>{"uri":"http://somelink"}</code>. |
| * @param reader |
| * @param entitySet |
| * @return link as string object |
| * @throws EntityProviderException |
| */ |
| public String readLink(final JsonReader reader, final EdmEntitySet entitySet) throws EntityProviderException { |
| try { |
| String result; |
| reader.beginObject(); |
| String nextName = reader.nextName(); |
| final boolean wrapped = FormatJson.D.equals(nextName); |
| if (wrapped) { |
| reader.beginObject(); |
| nextName = reader.nextName(); |
| } |
| if (FormatJson.URI.equals(nextName) && reader.peek() == JsonToken.STRING) { |
| result = reader.nextString(); |
| } else { |
| throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent( |
| FormatJson.D + " or " + FormatJson.URI).addContent(nextName)); |
| } |
| reader.endObject(); |
| if (wrapped) { |
| reader.endObject(); |
| } |
| |
| reader.peek(); // to assert end of structure or document |
| |
| 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); |
| } |
| } |
| |
| /** |
| * Reads a collection of links, optionally wrapped in a "d" object, |
| * and optionally wrapped in an "results" object, where an additional "__count" |
| * object could appear on the same level as the "results". |
| * @param reader |
| * @param entitySet |
| * @return links as List of Strings |
| * @throws EntityProviderException |
| */ |
| public List<String> readLinks(final JsonReader reader, final EdmEntitySet entitySet) throws EntityProviderException { |
| List<String> links = null; |
| int openedObjects = 0; |
| |
| try { |
| String nextName; |
| if (reader.peek() == JsonToken.BEGIN_ARRAY) { |
| nextName = FormatJson.RESULTS; |
| } else { |
| reader.beginObject(); |
| openedObjects++; |
| nextName = reader.nextName(); |
| } |
| if (FormatJson.D.equals(nextName)) { |
| if (reader.peek() == JsonToken.BEGIN_ARRAY) { |
| nextName = FormatJson.RESULTS; |
| } else { |
| reader.beginObject(); |
| openedObjects++; |
| nextName = reader.nextName(); |
| } |
| } |
| FeedMetadataImpl feedMetadata = new FeedMetadataImpl(); |
| if (FormatJson.COUNT.equals(nextName)) { |
| JsonFeedConsumer.readInlineCount(reader, feedMetadata); |
| nextName = reader.nextName(); |
| } |
| if (FormatJson.RESULTS.equals(nextName)) { |
| links = readLinksArray(reader); |
| } else { |
| throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent(FormatJson.RESULTS) |
| .addContent(nextName)); |
| } |
| if (reader.hasNext() && reader.peek() == JsonToken.NAME) { |
| if (FormatJson.COUNT.equals(reader.nextName())) { |
| JsonFeedConsumer.readInlineCount(reader, feedMetadata); |
| } else { |
| throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent(FormatJson.COUNT) |
| .addContent(nextName)); |
| } |
| } |
| for (; openedObjects > 0; openedObjects--) { |
| reader.endObject(); |
| } |
| |
| reader.peek(); // to assert end of document |
| } 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); |
| } |
| |
| return links; |
| } |
| |
| private List<String> readLinksArray(final JsonReader reader) throws IOException, EntityProviderException { |
| List<String> links = new ArrayList<String>(); |
| |
| reader.beginArray(); |
| while (reader.hasNext()) { |
| reader.beginObject(); |
| String nextName = reader.nextName(); |
| if (FormatJson.URI.equals(nextName) && reader.peek() == JsonToken.STRING) { |
| links.add(reader.nextString()); |
| } else { |
| throw new EntityProviderException(EntityProviderException.INVALID_CONTENT.addContent(FormatJson.URI) |
| .addContent(nextName)); |
| } |
| reader.endObject(); |
| } |
| reader.endArray(); |
| |
| return links; |
| } |
| } |