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 *
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 *
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 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
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 * file and include the License file at packager/legal/LICENSE.txt.
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package com.sun.grizzly.comet.handlers;

import com.sun.grizzly.comet.CometEvent;
import com.sun.grizzly.comet.CometHandler;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * Simple {@link CometHandler} that write (using a {@link PrintWriter})
 * all messages ({@link CometEvent#attachment} it receive. This {@link CometHandler}
 * just reflect everything, without filtering, the result of a {@link CometContext#notify).
 * 
 * @author Jeanfrancois Arcand
 */
public class ReflectorCometHandler implements CometHandler {

    // Simple PrintWrite
    protected PrintWriter printWriter;

    // Message send when the connection terminate or gets interrupted.
    private String startingMessage = "";
    
    // Message send when the connection terminate or gets interrupted.
    private String endingMessage = "";
        
    // Is http-streamin mode used 
    private boolean useStreaming = true;

    
    /**
     * Create a reflector. 
     */
    public ReflectorCometHandler(){
    }    
    
    /**
     * Create a reflector. 
     * @param useStreaming should the connection be resumed on the first push, 
     *                     or never resumed from the {@link ReflectorCometHandler#onEvent}. Default is true. 
     */
    public ReflectorCometHandler(boolean useStreaming){
        this.useStreaming = useStreaming;
    }
    
    /**
     * Create a reflector. 
     * @param useStreaming should the connection be resumed on the first push, 
     *                     or never resumed from the {@link ReflectorCometHandler#onEvent}. Default is true. 
     * @param endingMessage Message send when the connection is about to be suspended
     *                      ({@link ReflectorCometHandler#onInitialize})
     *                      or gets interrupted ({@link ReflectorCometHandler#onInterrupt}) 
     * @param endingMessage Message send when the connection terminate ({@link ReflectorCometHandler#onTerminate})
     *                      or gets interrupted ({@link ReflectorCometHandler#onInterrupt})
     */
    public ReflectorCometHandler(boolean useStreaming, String startingMessage,String endingMessage){
        this.useStreaming = useStreaming;
        this.startingMessage = startingMessage;
        this.endingMessage = endingMessage;
    }
    
    /**
     * Attach a {@link PrintWriter} that will be used to write the returned value of
     * {@link CometEvent#attachment}
     * 
     * @param printWriter {@link PrintWriter} that will be used to write the returned value of
     * {@link CometEvent#attachment}
     */
    public void attach(PrintWriter printWriter) {
        this.printWriter = printWriter;
    }

    /**
     * Write {@link CometEvent#attachment} and resume the connection if 
     * {@link ReflectorCometHandler#useStreaming} is false
     * @param event
     * @throws java.io.IOException
     */
    public void onEvent(CometEvent event) throws IOException {
        try {
            if (event.getType() != CometEvent.READ) {
                printWriter.println(event.attachment());
                printWriter.flush();
                
                if (!useStreaming){
                    event.getCometContext().resumeCometHandler(this);
                }
            }
        } catch (Throwable t) {
            throw new IOException(t.getMessage());
        }
    }

    /**
     * Send the  {@link ReflectorCometHandler#startingMessage} before the
     * connection get suspended.
     * 
     * @param event (@link CometEvent}
     * @throws java.io.IOException
     */
    public void onInitialize(CometEvent event) throws IOException {
        printWriter.println(startingMessage);
        printWriter.flush();
    }

    /**
     * Send the  {@link ReflectorCometHandler#endingMessage} before the
     * connection get terminated.
     * 
     * @param event (@link CometEvent}
     * @throws java.io.IOException
     */    
    public void onTerminate(CometEvent event) throws IOException {
        onInterrupt(event);
    }
    
    /**
     * Send the  {@link ReflectorCometHandler#endingMessage} before the
     * connection get interupted.
     * 
     * @param event (@link CometEvent}
     * @throws java.io.IOException
     */
    public void onInterrupt(CometEvent event) throws IOException {
        printWriter.println(endingMessage);
    }
}