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1   /**
2    * This file Copyright (c) 2017 Magnolia International
3    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
4    *
5    *
6    * This file is dual-licensed under both the Magnolia
7    * Network Agreement and the GNU General Public License.
8    * You may elect to use one or the other of these licenses.
9    *
10   * This file is distributed in the hope that it will be
11   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12   * implied warranty of MERCHANTABILITY or FITNESS FOR A
13   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14   * Redistribution, except as permitted by whichever of the GPL
15   * or MNA you select, is prohibited.
16   *
17   * 1. For the GPL license (GPL), you can redistribute and/or
18   * modify this file under the terms of the GNU General
19   * Public License, Version 3, as published by the Free Software
20   * Foundation.  You should have received a copy of the GNU
21   * General Public License, Version 3 along with this program;
22   * if not, write to the Free Software Foundation, Inc., 51
23   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24   *
25   * 2. For the Magnolia Network Agreement (MNA), this file
26   * and the accompanying materials are made available under the
27   * terms of the MNA which accompanies this distribution, and
28   * is available at http://www.magnolia-cms.com/mna.html
29   *
30   * Any modifications to this file must keep this entire header
31   * intact.
32   *
33   */
34  package info.magnolia.rest.delivery.jcr;
35  
36  import java.io.IOException;
37  import java.io.OutputStream;
38  import java.lang.annotation.Annotation;
39  import java.lang.reflect.Type;
40  
41  import javax.jcr.NodeIterator;
42  import javax.json.Json;
43  import javax.json.stream.JsonGenerator;
44  import javax.ws.rs.Produces;
45  import javax.ws.rs.WebApplicationException;
46  import javax.ws.rs.core.Context;
47  import javax.ws.rs.core.MediaType;
48  import javax.ws.rs.core.MultivaluedMap;
49  import javax.ws.rs.ext.MessageBodyWriter;
50  import javax.ws.rs.ext.Provider;
51  import javax.ws.rs.ext.Providers;
52  
53  /**
54   * "Providers" is injected to get NodeIteratorWriter and delegate the job of writing to nodes to NodeIteratorWriter.
55   * Since NodeIteratorWriter and NodesResultWriter share the same JsonGenerator, it is passed along with OutputStream using OutputStreamWrapper.
56   */
57  @Provider
58  @Produces({MediaType.APPLICATION_JSON})
59  public class NodesResultWriter implements MessageBodyWriter<NodesResult> {
60  
61      @Context
62      private Providers providers;
63  
64      @Override
65      public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
66          return NodesResult.class.isAssignableFrom(type);
67      }
68  
69      @Override
70      public long getSize(NodesResult nodeIterator, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
71          // As of JAX-RS 2.0, the method has been deprecated and the value returned by the method is ignored by a JAX-RS runtime.
72          return -1;
73      }
74  
75      @Override
76      public void writeTo(NodesResult nodesResult, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException {
77  
78          MessageBodyWriter<NodeIterator> nodeIteratorWriter = providers.getMessageBodyWriter(NodeIterator.class, genericType, annotations, mediaType);
79          NodeIterator nodeIterator = nodesResult.getResults();
80  
81          try (JsonGenerator jsonGenerator = Json.createGenerator(entityStream)) {
82              OutputStream wrappedEntityStream = new OutputStreamWrapper(entityStream, jsonGenerator);
83  
84              jsonGenerator.writeStartObject();
85              //TODO temporary exclude total query metadata as api is not ready to provide estimated query size.
86  //            jsonGenerator.write("total", nodesResult.getTotal());
87              jsonGenerator.writeStartArray("results");
88              nodeIteratorWriter.writeTo(nodeIterator, type, genericType, annotations, mediaType, httpHeaders, wrappedEntityStream);
89              jsonGenerator.writeEnd();
90          }
91      }
92  
93      /**
94       * Used for testing.
95       */
96      void setProviders(Providers providers) {
97          this.providers = providers;
98      }
99  }