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1   package org.apache.maven.plugin.war.util;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import com.thoughtworks.xstream.XStream;
23  import com.thoughtworks.xstream.io.xml.DomDriver;
24  import org.apache.maven.model.Dependency;
25  import org.codehaus.plexus.util.IOUtil;
26  import org.codehaus.plexus.util.ReaderFactory;
27  import org.codehaus.plexus.util.WriterFactory;
28  
29  import java.io.File;
30  import java.io.IOException;
31  import java.io.Reader;
32  import java.io.Writer;
33  
34  /**
35   * Serializes {@link WebappStructure} back and forth.
36   *
37   * @author Stephane Nicoll
38   * @version $Id: WebappStructureSerializer.java 985593 2010-08-14 22:12:09Z dennisl $
39   */
40  public class WebappStructureSerializer
41  {
42  
43      private static final XStream xStream;
44  
45      static
46      {
47          xStream = new XStream( new DomDriver() );
48  
49          // Register aliases
50          xStream.alias( "webapp-structure", WebappStructure.class );
51          xStream.alias( "path-set", PathSet.class );
52          xStream.alias( "dependency", Dependency.class );
53  
54      }
55  
56      /**
57       * Creates a new instance of the serializer.
58       */
59      public WebappStructureSerializer()
60      {
61      }
62  
63  
64      /**
65       * Reads the {@link WebappStructure} from the specified file.
66       *
67       * @param file the file containing the webapp structure
68       * @return the webapp structure
69       * @throws IOException if an error occurred while reading the structure
70       */
71      public WebappStructure fromXml( File file )
72          throws IOException
73      {
74          Reader reader = null;
75  
76          try
77          {
78              reader = ReaderFactory.newXmlReader( file );
79              return (WebappStructure) xStream.fromXML( reader );
80          }
81          finally
82          {
83              IOUtil.close( reader );
84          }
85      }
86  
87      /**
88       * Saves the {@link WebappStructure} to the specified file.
89       *
90       * @param webappStructure the structure to save
91       * @param targetFile      the file to use to save the structure
92       * @throws IOException if an error occurred while saving the webapp structure
93       */
94      public void toXml( WebappStructure webappStructure, File targetFile )
95          throws IOException
96      {
97          Writer writer = null;
98          try
99          {
100             if ( !targetFile.getParentFile().exists() && !targetFile.getParentFile().mkdirs() )
101             {
102                 throw new IOException(
103                     "Could not create parent [" + targetFile.getParentFile().getAbsolutePath() + "]" );
104             }
105 
106             if ( !targetFile.exists() && !targetFile.createNewFile() )
107             {
108                 throw new IOException( "Could not create file [" + targetFile.getAbsolutePath() + "]" );
109             }
110             writer = WriterFactory.newXmlWriter( targetFile );
111             xStream.toXML( webappStructure, writer );
112         }
113         finally
114         {
115             IOUtil.close( writer );
116         }
117     }
118 }