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1   /*
2    * Copyright 2014 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package io.netty.handler.codec.xml;
17  
18  import com.fasterxml.aalto.AsyncByteArrayFeeder;
19  import com.fasterxml.aalto.AsyncXMLInputFactory;
20  import com.fasterxml.aalto.AsyncXMLStreamReader;
21  import com.fasterxml.aalto.stax.InputFactoryImpl;
22  import io.netty.buffer.ByteBuf;
23  import io.netty.channel.ChannelHandlerContext;
24  import io.netty.handler.codec.ByteToMessageDecoder;
25  
26  import javax.xml.stream.XMLStreamConstants;
27  import javax.xml.stream.XMLStreamException;
28  import java.util.List;
29  
30  /**
31   * Async XML decoder based on <a href="https://github.com/FasterXML/aalto-xml">Aalto XML parser</a>.
32   *
33   * Parses the incoming data into one of XML messages defined in this package.
34   */
35  
36  public class XmlDecoder extends ByteToMessageDecoder {
37  
38      private static final AsyncXMLInputFactory XML_INPUT_FACTORY = new InputFactoryImpl();
39      private static final XmlDocumentEnd XML_DOCUMENT_END = XmlDocumentEnd.INSTANCE;
40  
41      private final AsyncXMLStreamReader<AsyncByteArrayFeeder> streamReader = XML_INPUT_FACTORY.createAsyncForByteArray();
42      private final AsyncByteArrayFeeder streamFeeder = (AsyncByteArrayFeeder) streamReader.getInputFeeder();
43  
44      @Override
45      protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
46          byte[] buffer = new byte[in.readableBytes()];
47          in.readBytes(buffer);
48          try {
49              streamFeeder.feedInput(buffer, 0, buffer.length);
50          } catch (XMLStreamException exception) {
51              in.skipBytes(in.readableBytes());
52              throw exception;
53          }
54  
55          while (!streamFeeder.needMoreInput()) {
56              int type = streamReader.next();
57              switch (type) {
58                  case XMLStreamConstants.START_DOCUMENT:
59                      out.add(new XmlDocumentStart(streamReader.getEncoding(), streamReader.getVersion(),
60                              streamReader.isStandalone(), streamReader.getCharacterEncodingScheme()));
61                      break;
62                  case XMLStreamConstants.END_DOCUMENT:
63                      out.add(XML_DOCUMENT_END);
64                      break;
65                  case XMLStreamConstants.START_ELEMENT:
66                      XmlElementStart elementStart = new XmlElementStart(streamReader.getLocalName(),
67                              streamReader.getName().getNamespaceURI(), streamReader.getPrefix());
68                      for (int x = 0; x < streamReader.getAttributeCount(); x++) {
69                          XmlAttribute attribute = new XmlAttribute(streamReader.getAttributeType(x),
70                                  streamReader.getAttributeLocalName(x), streamReader.getAttributePrefix(x),
71                                  streamReader.getAttributeNamespace(x), streamReader.getAttributeValue(x));
72                          elementStart.attributes().add(attribute);
73                      }
74                      for (int x = 0; x < streamReader.getNamespaceCount(); x++) {
75                          XmlNamespace namespace = new XmlNamespace(streamReader.getNamespacePrefix(x),
76                                  streamReader.getNamespaceURI(x));
77                          elementStart.namespaces().add(namespace);
78                      }
79                      out.add(elementStart);
80                      break;
81                  case XMLStreamConstants.END_ELEMENT:
82                      XmlElementEnd elementEnd = new XmlElementEnd(streamReader.getLocalName(),
83                              streamReader.getName().getNamespaceURI(), streamReader.getPrefix());
84                      for (int x = 0; x < streamReader.getNamespaceCount(); x++) {
85                          XmlNamespace namespace = new XmlNamespace(streamReader.getNamespacePrefix(x),
86                                  streamReader.getNamespaceURI(x));
87                          elementEnd.namespaces().add(namespace);
88                      }
89                      out.add(elementEnd);
90                      break;
91                  case XMLStreamConstants.PROCESSING_INSTRUCTION:
92                      out.add(new XmlProcessingInstruction(streamReader.getPIData(), streamReader.getPITarget()));
93                      break;
94                  case XMLStreamConstants.CHARACTERS:
95                      out.add(new XmlCharacters(streamReader.getText()));
96                      break;
97                  case XMLStreamConstants.COMMENT:
98                      out.add(new XmlComment(streamReader.getText()));
99                      break;
100                 case XMLStreamConstants.SPACE:
101                     out.add(new XmlSpace(streamReader.getText()));
102                     break;
103                 case XMLStreamConstants.ENTITY_REFERENCE:
104                     out.add(new XmlEntityReference(streamReader.getLocalName(), streamReader.getText()));
105                     break;
106                 case XMLStreamConstants.DTD:
107                     out.add(new XmlDTD(streamReader.getText()));
108                     break;
109                 case XMLStreamConstants.CDATA:
110                     out.add(new XmlCdata(streamReader.getText()));
111                     break;
112             }
113         }
114     }
115 
116 }