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1   package org.apache.maven.plugin.invoker;
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 org.apache.maven.plugin.logging.Log;
23  import org.apache.maven.shared.invoker.InvocationOutputHandler;
24  import org.codehaus.plexus.util.IOUtil;
25  
26  import java.io.File;
27  import java.io.FileOutputStream;
28  import java.io.IOException;
29  import java.io.PrintStream;
30  
31  /**
32   * @version $Id: FileLogger.java 684034 2008-08-08 18:20:31Z bentmann $
33   */
34  class FileLogger
35      implements InvocationOutputHandler
36  {
37  
38      /**
39       * The path to the log file.
40       */
41      private File file;
42  
43      /**
44       * The underlying file stream this logger writes to.
45       */
46      private PrintStream stream;
47  
48      /**
49       * A flag whether the output stream should be closed during finalization of this logger.
50       */
51      private boolean shouldFinalize = true;
52  
53      /**
54       * The optional mojo logger to additionally write messages to, can be <code>nulll</code>.
55       */
56      private final Log log;
57  
58      /**
59       * Creates a new logger that writes to the specified file.
60       * 
61       * @param outputFile The path to the output file, must not be <code>null</code>.
62       * @throws IOException If the output file could not be created.
63       */
64      public FileLogger( File outputFile )
65          throws IOException
66      {
67          this( outputFile, null );
68      }
69  
70      /**
71       * Creates a new logger that writes to the specified file and optionally mirrors messages to the given mojo logger.
72       * 
73       * @param outputFile The path to the output file, must not be <code>null</code>.
74       * @param log The mojo logger to additionally output messages to, may be <code>null</code> if not used.
75       * @throws IOException If the output file could not be created.
76       */
77      public FileLogger( File outputFile, Log log )
78          throws IOException
79      {
80          this.file = outputFile;
81          this.log = log;
82  
83          outputFile.getParentFile().mkdirs();
84          stream = new PrintStream( new FileOutputStream( outputFile ) );
85  
86          Runnable finalizer = new Runnable()
87          {
88              public void run()
89              {
90                  try
91                  {
92                      finalize();
93                  }
94                  catch ( Throwable e )
95                  {
96                      // ignore
97                  }
98              }
99          };
100 
101         Runtime.getRuntime().addShutdownHook( new Thread( finalizer ) );
102     }
103 
104     /**
105      * Gets the path to the output file.
106      * 
107      * @return The path to the output file, never <code>null</code>.
108      */
109     public File getOutputFile()
110     {
111         return file;
112     }
113 
114     /**
115      * Gets the underlying stream used to write message to the log file.
116      * 
117      * @return The underlying stream used to write message to the log file, never <code>null</code>.
118      */
119     public PrintStream getPrintStream()
120     {
121         return stream;
122     }
123 
124     /**
125      * Writes the specified line to the log file and optionally to the mojo logger.
126      * 
127      * @param line The message to log.
128      */
129     public void consumeLine( String line )
130     {
131         stream.println( line );
132         stream.flush();
133 
134         if ( log != null )
135         {
136             log.info( line );
137         }
138     }
139 
140     /**
141      * Closes the underlying file stream.
142      */
143     public void close()
144     {
145         if ( stream != null )
146         {
147             stream.flush();
148         }
149 
150         IOUtil.close( stream );
151     }
152 
153     /**
154      * Closes the underlying file stream.
155      */
156     protected void finalize()
157     {
158         if ( shouldFinalize )
159         {
160             close();
161         }
162     }
163 }