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1   /*
2    * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
3    * The software in this package is published under the terms of the CPAL v1.0
4    * license, a copy of which has been included with this distribution in the
5    * LICENSE.txt file.
6    */
7   package org.mule.transport.file;
8   
9   import org.mule.api.MuleContext;
10  import org.mule.api.MuleMessage;
11  import org.mule.api.context.MuleContextAware;
12  import org.mule.api.expression.ExpressionManager;
13  import org.mule.util.TemplateParser;
14  
15  import java.text.MessageFormat;
16  
17  /**
18   * <code>ExpressionFilenameParser</code> can use any expression language supported by Mule
19   * to construct a file name for the current message.  Expressions can be xpath, xquery, ognl, mvel,
20   * header, function and more. For more information see http://www.mulesoft.org/documentation/display/MULE3USER/Using+Expressions.
21   * <p/>
22   * For example an xpath expression can be defined to pull a message id out of an xml message and 
23   * use that as the file name -
24   * <code>
25   * #[xpath:/message/header/@id]
26   * </code>
27   * <p/>
28   * This parser superseeds the (now removed) <code>org.mule.transport.file.SimpleFilenameParser</code>
29   * which has been kept in Mule 2 for compatibility. The following demonstrates how to achieve the 
30   * same results when using the <code>ExpressionFilenameParser</code> over the 
31   * <code>SimpleFilenameParser</code>
32   * <ul>
33   * <li>#[DATE] : #[function:datestamp]</li>
34   * <li>#[DATE:yy-MM-dd] : #[function:datestamp-yy-MM-dd]</li>
35   * <li>#[SYSTIME] : #[function:systime]</li>
36   * <li>#[UUID] : #[function:uuid]</li>
37   * <li>#[ORIGINALNAME] : #[header:originalFilename]</li>
38   * <li>#[COUNT] : #[function:count] - note that this is a global counter.</li>
39   * <li>#[&lt;Message Property Name&gt;] : #[header:&lt;Message Property Name&gt;]</li>
40   * </ul>
41   */
42  public class ExpressionFilenameParser implements FilenameParser, MuleContextAware
43  {
44      public static final String DEFAULT_DATE_FORMAT = "dd-MM-yy_HH-mm-ss.SSS";
45      public static final String DEFAULT_EXPRESSION = MessageFormat.format("{0}function:uuid{1}.dat",
46                                                                           ExpressionManager.DEFAULT_EXPRESSION_PREFIX,
47                                                                           ExpressionManager.DEFAULT_EXPRESSION_POSTFIX);
48  
49      private final TemplateParser wigglyMuleParser = TemplateParser.createMuleStyleParser();
50      private final TemplateParser squareParser = TemplateParser.createSquareBracesStyleParser();
51  
52      protected MuleContext muleContext;
53  
54      public void setMuleContext(MuleContext context)
55      {
56          this.muleContext = context;
57      }
58  
59      public String getFilename(MuleMessage message, String expression)
60      {
61          if (expression == null)
62          {
63              expression = DEFAULT_EXPRESSION;
64          }
65  
66          if (expression.indexOf(ExpressionManager.DEFAULT_EXPRESSION_PREFIX) > -1)
67          {
68              return getFilename(message, expression, wigglyMuleParser);
69          }
70          else
71          {
72              return getFilename(message, expression, squareParser);
73          }
74      }
75  
76      protected String getFilename(final MuleMessage message, String expression, TemplateParser parser)
77      {
78          return parser.parse(new TemplateParser.TemplateCallback()
79          {
80              public Object match(String token)
81              {
82                  return muleContext.getExpressionManager().evaluate(token, message);
83              }
84          }, expression);
85      }
86  }