ObjectEchoClientHandler.java

/**        
 * Copyright (c) 2013 by 苏州科大国创信息技术有限公司.    
 */    
package com.ustcinfo.netty.object.simple;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Handler implementation for the object echo client.  It initiates the
 * ping-pong traffic between the object echo client and server by sending the
 * first message to the server.
 * 
 * Create on @2013-8-15 @上午10:13:16 
 * @author bsli@ustcinfo.com
 */
public class ObjectEchoClientHandler extends ChannelInboundHandlerAdapter {

    private static final Logger logger = Logger.getLogger(
            ObjectEchoClientHandler.class.getName());

    private final List<Integer> firstMessage;

    /**
     * Creates a client-side handler.
     */
    public ObjectEchoClientHandler(int firstMessageSize) {
        if (firstMessageSize <= 0) {
            throw new IllegalArgumentException(
                    "firstMessageSize: " + firstMessageSize);
        }
        firstMessage = new ArrayList<Integer>(firstMessageSize);
        for (int i = 0; i < firstMessageSize; i ++) {
            firstMessage.add(Integer.valueOf(i));
        }
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // Send the first message if this handler is a client-side handler.
        ctx.writeAndFlush(firstMessage);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        // Echo back the received object to the server.
        ctx.write(msg);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(
            ChannelHandlerContext ctx, Throwable cause) throws Exception {
        logger.log(
                Level.WARNING,
                "Unexpected exception from downstream.", cause);
        ctx.close();
    }
}