/*
    * 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.hadoop.chukwa.datacollection.adaptor.jms;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import javax.jms.Message;
  import javax.jms.TextMessage;
  import javax.jms.JMSException;
  
  /**
   * Basic JMSMessageTransformer that uses the payload message of a JMS
   * TextMessage as the Chukwa record payload. If the message is not an instance
   * of TextMessage, or it is, but the payload is null or empty, returns null.
   */
  public class JMSTextMessageTransformer implements JMSMessageTransformer {
    protected Log log = LogFactory.getLog(getClass());
  
    public String parseArgs(String s) {
      return s;      
    }
  
    public byte[] transform(Message message) throws JMSException {
      if (!(message instanceof TextMessage)) {
        log.warn("Invalid message type received: " + message);
        return null;
      }
  
      String text = ((TextMessage)message).getText();
      if (text != null && text.length() > 0) {
        return text.getBytes();
      }
  
      return null;
    }
  }