destinationtag.java

来自「jakarta-taglibs」· Java 代码 · 共 103 行

/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.taglibs.jms;

import javax.jms.Destination;
import javax.jms.JMSException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyContent;

import org.apache.commons.messenger.Messenger;

/** Creates a Destination object from a String name.
  *
  * @author <a href="mailto:[e-mail]">James Strachan</a>
  * @version $Revision: 1.2 $
  */
public class DestinationTag extends AbstractBodyTag {

    /** The variable name to create */
    private String var;
        
    /** Stores the name of the map entry */
    private String name;
        
    // BodyTag interface
    //-------------------------------------------------------------------------                    
    public int doStartTag() throws JspException {
        if ( name != null ) {
            exportDestination();
            return SKIP_BODY;
        }
        return EVAL_BODY_TAG;
    }
    
    public int doAfterBody() throws JspException {
        BodyContent body = getBodyContent();
        name = body.getString();
        body.clearBody();
        exportDestination();
        return EVAL_PAGE;
    }
    
    public void release() {
        name = null;
        var = null;
    }
    
    // Properties
    //-------------------------------------------------------------------------                    
    
    /** Sets the name of the Destination
      */
    public void setName(String name) {
        this.name = name;
    }
    
    /** Sets the variable name to use for the Destination
      */
    public void setVar(String var) {
        this.var = var;
    }
    
    // Implementation methods
    //-------------------------------------------------------------------------                        
    protected void exportDestination() throws JspException {
        try {
            ConnectionContext messengerTag = (ConnectionContext) findAncestorWithClass( this, ConnectionContext.class );
            if ( messengerTag == null ) {
                throw new JspException("<jms:destination> tag must be within a <jms:connection> or <jms:send> or <jms:receive> tag");
            }
            Messenger messenger = messengerTag.getConnection();
            Destination destination = messenger.getDestination( name );
            if ( var != null ) {
                pageContext.setAttribute( var, destination );
            }
            else {
                MessageOperationTag tag = (MessageOperationTag) findAncestorWithClass( this, MessageOperationTag.class );
                if ( tag == null ) {
                    throw new JspException("<jms:destination> tag must be within a <jms:send> or <jms:receive> tag or the 'var' attribute should be specified");
                }
                tag.setDestination( destination );
            }
        }
        catch (JMSException e) {
            throw new JspException( "Failed to create the Destination for: " + name );
        }
    }    
}