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 * 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.james.transport.mailets;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage ;

import org.apache.mailet.GenericMailet ;
import org.apache.mailet.Mail ;

/**
 * Adds a specified header and value to the message.
 *
 * Sample configuration:
 *
 * <mailet match="All" class="AddHeader">
 *   <name>X-MailetHeader</name>
 *   <value>TheHeaderValue</value>
 * </mailet>
 *
 * @version 1.0.0, 2002-09-11
 */
public class SetMimeHeader
       extends GenericMailet {

    /**
     * The name of the header to be added.
     */
    private String headerName;

    /**
     * The value to be set for the header.
     */
    private String headerValue;

    /**
     * Initialize the mailet.
     */
    public void init() throws MessagingException {
        headerName = getInitParameter("name");
        headerValue = getInitParameter("value");
        
        // Check if needed config values are used
        if (headerName == null || headerName.equals("") || headerValue == null
                || headerValue.equals("")) {
            throw new MessagingException("Please configure a name and a value");
        }
    }

    /**
     * Takes the message and adds a header to it.
     *
     * @param mail the mail being processed
     *
     * @throws MessagingException if an error arises during message processing
     */
    public void service(Mail mail) {
        try {
            MimeMessage message = mail.getMessage () ;

            //Set the header name and value (supplied at init time).
            message.setHeader(headerName, headerValue);
            message.saveChanges();
        } catch (javax.mail.MessagingException me) {
            log (me.getMessage());
        }
    }

    /**
     * Return a string describing this mailet.
     *
     * @return a string describing this mailet
     */
    public String getMailetInfo() {
        return "SetMimeHeader Mailet" ;
    }

}