expressionfilenameparser.java

提供ESB 应用mule源代码 提供ESB 应用mule源代码

/*
 * $Id: ExpressionFilenameParser.java 13054 2008-10-10 21:45:36Z dfeist $
 * --------------------------------------------------------------------------------------
 * Copyright (c) MuleSource, Inc.  All rights reserved.  http://www.mulesource.com
 *
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */

package org.mule.transport.file;

import org.mule.api.transport.MessageAdapter;
import org.mule.util.TemplateParser;
import org.mule.util.expression.ExpressionEvaluatorManager;

import java.text.MessageFormat;

/**
 * <code>ExpressionFilenameParser</code> can use any expression language supported by Mule
 * to construct a file name for the current message.  Expressions can be xpath, xquery, ognl, mvel, header, function
 * and more. For more information see http://muledocs.org/v2/Expressions.
 * <p/>
 * For example an xpath expression can be defined to pull a message id out of an xml message and use that as the file name -
 * <code>
 * #[xpath:/message/header/@id]
 * </code>
 * <p/>
 * This parser superseeds the {@link org.mule.transport.file.SimpleFilenameParser} which has been kept in Mule 2 for
 * compatibility. The following demonstrates how to achieve the same results when using the <code>ExpressionFilenameParser</code>
 * over the {@link org.mule.transport.file.SimpleFilenameParser}.
 * <ul>
 * <li>#[DATE] : #[function:dateStamp]</li>
 * <li>#[DATE:yy-MM-dd] : #[function:dateStamp(yy-MM-dd)]</li>
 * <li>#[SYSTIME] : #[function:systime]</li>
 * <li>#[UUID] : #[function:uuid]</li>
 * <li>#[ORIGINALNAME] : #[header:originalFilename]</li>
 * <li>#[COUNT] : #[function:counter] - note that this is a global counter. If you want a local counter per file connector then you should use the {@link org.mule.transport.file.SimpleFilenameParser}.</li>
 * <li>#[&lt;Message Property Name>] : #[header:&lt;Message Property Name>]</li>
 * </ul>
 */

public class ExpressionFilenameParser implements FilenameParser
{
    public static final String DEFAULT_DATE_FORMAT = "dd-MM-yy_HH-mm-ss.SSS";
    public static final String DEFAULT_EXPRESSION = MessageFormat.format("{0}function:uuid{1}.dat",
                                                                         ExpressionEvaluatorManager.DEFAULT_EXPRESSION_PREFIX,
                                                                         ExpressionEvaluatorManager.DEFAULT_EXPRESSION_POSTFIX);

    private final TemplateParser wigglyMuleParser = TemplateParser.createMuleStyleParser();
    private final TemplateParser squareParser = TemplateParser.createSquareBracesStyleParser();

    public String getFilename(MessageAdapter adapter, String expression)
    {
        if (expression == null)
        {
            return expression = DEFAULT_EXPRESSION;
        }

        if (expression.indexOf(ExpressionEvaluatorManager.DEFAULT_EXPRESSION_PREFIX) > -1)
        {
            return getFilename(adapter, expression, wigglyMuleParser);
        }
        else
        {
            return getFilename(adapter, expression, squareParser);
        }
    }


    protected String getFilename(final MessageAdapter adapter, String expression, TemplateParser parser)
    {
        return parser.parse(new TemplateParser.TemplateCallback()
        {
            public Object match(String token)
            {
                return ExpressionEvaluatorManager.evaluate(token, adapter);
            }
        }, expression);
    }
}