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1   package org.apache.maven.shared.scriptinterpreter;
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.codehaus.plexus.util.IOUtil;
24  
25  import java.io.File;
26  import java.io.FileOutputStream;
27  import java.io.IOException;
28  import java.io.PrintStream;
29  
30  /**
31   * @version $Id: FileLogger.java 1194996 2011-10-29 19:42:00Z olamy $
32   */
33  public class FileLogger
34      implements ExecutionLogger
35  {
36  
37      /**
38       * The path to the log file.
39       */
40      private File file;
41  
42      /**
43       * The underlying file stream this logger writes to.
44       */
45      private PrintStream stream;
46  
47      /**
48       * A flag whether the output stream should be closed during finalization of this logger.
49       */
50      private boolean shouldFinalize = true;
51  
52      /**
53       * The optional mojo logger to additionally write messages to, can be <code>nulll</code>.
54       */
55      private final Log log;
56  
57      /**
58       * Creates a new logger that writes to the specified file.
59       * 
60       * @param outputFile The path to the output file, must not be <code>null</code>.
61       * @throws java.io.IOException If the output file could not be created.
62       */
63      public FileLogger( File outputFile )
64          throws IOException
65      {
66          this( outputFile, null );
67      }
68  
69      /**
70       * Creates a new logger that writes to the specified file and optionally mirrors messages to the given mojo logger.
71       *
72       * @param outputFile The path to the output file, must not be <code>null</code>.
73       * @param log The mojo logger to additionally output messages to, may be <code>null</code> if not used.
74       * @throws java.io.IOException If the output file could not be created.
75       */
76      public FileLogger( File outputFile, Log log )
77          throws IOException
78      {
79          this.file = outputFile;
80          this.log = log;
81  
82          outputFile.getParentFile().mkdirs();
83          stream = new PrintStream( new FileOutputStream( outputFile ) );
84  
85          Runnable finalizer = new Runnable()
86          {
87              public void run()
88              {
89                  try
90                  {
91                      finalize();
92                  }
93                  catch ( Throwable e )
94                  {
95                      // ignore
96                  }
97              }
98          };
99  
100         Runtime.getRuntime().addShutdownHook( new Thread( finalizer ) );
101     }
102 
103     /**
104      * Gets the path to the output file.
105      * 
106      * @return The path to the output file, never <code>null</code>.
107      */
108     public File getOutputFile()
109     {
110         return file;
111     }
112 
113     /**
114      * Gets the underlying stream used to write message to the log file.
115      * 
116      * @return The underlying stream used to write message to the log file, never <code>null</code>.
117      */
118     public PrintStream getPrintStream()
119     {
120         return stream;
121     }
122 
123     /**
124      * Writes the specified line to the log file and optionally to the mojo logger.
125      * 
126      * @param line The message to log.
127      */
128     public void consumeLine( String line )
129     {
130         stream.println( line );
131         stream.flush();
132 
133         if ( log != null )
134         {
135             log.info( line );
136         }
137     }
138 
139     /**
140      * Closes the underlying file stream.
141      */
142     public void close()
143     {
144         if ( stream != null )
145         {
146             stream.flush();
147         }
148 
149         IOUtil.close( stream );
150     }
151 
152     /**
153      * Closes the underlying file stream.
154      */
155     protected void finalize()
156     {
157         if ( shouldFinalize )
158         {
159             close();
160         }
161     }
162 }