components/camel-jms/src/main/java/org/apache/camel/component/jms/JmsMessageHelper.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.camel.component.jms;

import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.jms.JMSException;
import javax.jms.Message;

/**
 * Utility class for {@link javax.jms.Message}.
 *
 * @version $Revision$
 */
public final class JmsMessageHelper {

    private JmsMessageHelper() {
    }

    /**
     * Removes the property from the JMS message.
     *
     * @param jmsMessage the JMS message
     * @param name       name of the property to remove
     * @return the old value of the property or <tt>null</tt> if not exists
     * @throws JMSException can be thrown
     */
    public static Object removeJmsProperty(Message jmsMessage, String name) throws JMSException {
        // check if the property exists
        if (!jmsMessage.propertyExists(name)) {
            return null;
        }

        Object answer = null;

        // store the properties we want to keep in a temporary map
        // as the JMS API is a bit strict as we are not allowed to
        // clear a single property, but must clear them all and redo
        // the properties
        Map<String, Object> map = new LinkedHashMap<String, Object>();
        Enumeration en = jmsMessage.getPropertyNames();
        while (en.hasMoreElements()) {
            String key = (String) en.nextElement();
            if (name.equals(key)) {
                answer = key;
            } else {
                map.put(key, jmsMessage.getObjectProperty(key));
            }
        }

        // redo the properties to keep
        jmsMessage.clearProperties();
        for (String key : map.keySet()) {
            jmsMessage.setObjectProperty(key, map.get(key));
        }

        return answer;
    }

    /**
     * Tests whether a given property with the name exists
     *
     * @param jmsMessage the JMS message
     * @param name       name of the property to test if exists
     * @return <tt>true</tt> if the property exists, <tt>false</tt> if not.
     * @throws JMSException can be thrown
     */
    public static boolean hasProperty(Message jmsMessage, String name) throws JMSException {
        Enumeration en = jmsMessage.getPropertyNames();
        while (en.hasMoreElements()) {
            String key = (String) en.nextElement();
            if (name.equals(key)) {
                return true;
            }
        }
        return false;
    }

}