View Javadoc

1   /*
2    * $Id: ExpressionFilenameParser.java 20321 2010-11-24 15:21:24Z dfeist $
3    * --------------------------------------------------------------------------------------
4    * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
5    *
6    * The software in this package is published under the terms of the CPAL v1.0
7    * license, a copy of which has been included with this distribution in the
8    * LICENSE.txt file.
9    */
10  
11  package org.mule.transport.file;
12  
13  import org.mule.api.MuleContext;
14  import org.mule.api.MuleMessage;
15  import org.mule.api.context.MuleContextAware;
16  import org.mule.api.expression.ExpressionManager;
17  import org.mule.util.TemplateParser;
18  
19  import java.text.MessageFormat;
20  
21  /**
22   * <code>ExpressionFilenameParser</code> can use any expression language supported by Mule
23   * to construct a file name for the current message.  Expressions can be xpath, xquery, ognl, mvel, 
24   * header, function and more. For more information see http://muledocs.org/v2/Expressions.
25   * <p/>
26   * For example an xpath expression can be defined to pull a message id out of an xml message and 
27   * use that as the file name -
28   * <code>
29   * #[xpath:/message/header/@id]
30   * </code>
31   * <p/>
32   * This parser superseeds the (now removed) <code>org.mule.transport.file.SimpleFilenameParser</code>
33   * which has been kept in Mule 2 for compatibility. The following demonstrates how to achieve the 
34   * same results when using the <code>ExpressionFilenameParser</code> over the 
35   * <code>SimpleFilenameParser</code>
36   * <ul>
37   * <li>#[DATE] : #[function:datestamp]</li>
38   * <li>#[DATE:yy-MM-dd] : #[function:datestamp-yy-MM-dd]</li>
39   * <li>#[SYSTIME] : #[function:systime]</li>
40   * <li>#[UUID] : #[function:uuid]</li>
41   * <li>#[ORIGINALNAME] : #[header:originalFilename]</li>
42   * <li>#[COUNT] : #[function:count] - note that this is a global counter.</li>
43   * <li>#[&lt;Message Property Name&gt;] : #[header:&lt;Message Property Name&gt;]</li>
44   * </ul>
45   */
46  public class ExpressionFilenameParser implements FilenameParser, MuleContextAware
47  {
48      public static final String DEFAULT_DATE_FORMAT = "dd-MM-yy_HH-mm-ss.SSS";
49      public static final String DEFAULT_EXPRESSION = MessageFormat.format("{0}function:uuid{1}.dat",
50                                                                           ExpressionManager.DEFAULT_EXPRESSION_PREFIX,
51                                                                           ExpressionManager.DEFAULT_EXPRESSION_POSTFIX);
52  
53      private final TemplateParser wigglyMuleParser = TemplateParser.createMuleStyleParser();
54      private final TemplateParser squareParser = TemplateParser.createSquareBracesStyleParser();
55  
56      protected MuleContext muleContext;
57  
58      public void setMuleContext(MuleContext context)
59      {
60          this.muleContext = context;
61      }
62  
63      public String getFilename(MuleMessage message, String expression)
64      {
65          if (expression == null)
66          {
67              expression = DEFAULT_EXPRESSION;
68          }
69  
70          if (expression.indexOf(ExpressionManager.DEFAULT_EXPRESSION_PREFIX) > -1)
71          {
72              return getFilename(message, expression, wigglyMuleParser);
73          }
74          else
75          {
76              return getFilename(message, expression, squareParser);
77          }
78      }
79  
80      protected String getFilename(final MuleMessage message, String expression, TemplateParser parser)
81      {
82          return parser.parse(new TemplateParser.TemplateCallback()
83          {
84              public Object match(String token)
85              {
86                  return muleContext.getExpressionManager().evaluate(token, message);
87              }
88          }, expression);
89      }
90  }