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Netty TCP粘包/拆包问题《二》

1.DelimiterBasedFrameDecoder：是以分隔符作为结束标志进行解决粘包/拆包问题

代码：

　EchoClient：客户端

　　

/*

 * Copyright 2012 The Netty Project

 *

 * The Netty Project 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 nettyTcp01.echo;

import io.netty.bootstrap.Bootstrap;

import io.netty.buffer.ByteBuf;

import io.netty.buffer.Unpooled;

import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelOption;

import io.netty.channel.EventLoopGroup;

import io.netty.channel.nio.NioEventLoopGroup;

import io.netty.channel.socket.SocketChannel;

import io.netty.channel.socket.nio.NioSocketChannel;

import io.netty.handler.codec.DelimiterBasedFrameDecoder;

import io.netty.handler.codec.string.StringDecoder;

public class EchoClient {

    public void connect(int port, String host) throws Exception {

        // 配置客户端NIO线程组

        EventLoopGroup group = new NioEventLoopGroup();

        try {

            Bootstrap b = new Bootstrap();

            b.group(group).channel(NioSocketChannel.class).option(ChannelOption.TCP_NODELAY, true)

                    .handler(new ChannelInitializer<SocketChannel>() {

                        @Override

                        public void initChannel(SocketChannel ch) throws Exception {

                            ByteBuf delimiter = Unpooled.copiedBuffer("$_".getBytes());

                            ch.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, delimiter));

                            ch.pipeline().addLast(new StringDecoder());

                            ch.pipeline().addLast(new EchoClientHandler());

                        }

                    });

            // 发起异步连接操作

            ChannelFuture f = b.connect(host, port).sync();

            // 当代客户端链路关闭

            f.channel().closeFuture().sync();

        } finally {

            // 优雅退出，释放NIO线程组

            group.shutdownGracefully();

        }

    }

    /**

     * @param args

     * @throws Exception

     */

    public static void main(String[] args) throws Exception {

        int port = 8080;

        String host = "127.0.0.1";

        if (args != null && args.length > 0) {

            try {

                port = Integer.valueOf(args[0]);

            } catch (NumberFormatException e) {

                // 采用默认值

            }

        }

        new EchoClient().connect(port, host);

    }

}

EchoClientHandler：客户端数据处理

/*

 * Copyright 2012 The Netty Project

 *

 * The Netty Project 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 nettyTcp01.echo;

import io.netty.buffer.Unpooled;

import io.netty.channel.ChannelHandlerAdapter;

import io.netty.channel.ChannelHandlerContext;

public class EchoClientHandler extends ChannelHandlerAdapter {

    private int counter;

    static final String ECHO_REQ = "Hi, Lilinfeng. Welcome to Netty.$_";

    /**

     * Creates a client-side handler.

     */

    public EchoClientHandler() {

    }

    @Override

    public void channelActive(ChannelHandlerContext ctx) {

        // ByteBuf buf = UnpooledByteBufAllocator.DEFAULT.buffer(ECHO_REQ

        // .getBytes().length);

        // buf.writeBytes(ECHO_REQ.getBytes());

        for (int i = 0; i < 10; i++) {

            ctx.writeAndFlush(Unpooled.copiedBuffer(ECHO_REQ.getBytes()));

        }

    }

    @Override

    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {

        String requestBody = (String) msg;

        System.out.println("This is " + ++counter + " times receive server : [" + requestBody + "]");

    }

    @Override

    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {

        ctx.flush();

    }

    @Override

    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {

        cause.printStackTrace();

        ctx.close();

    }

}

EchoServer：服务器端

/*

 * Copyright 2012 The Netty Project

 *

 * The Netty Project 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 nettyTcp01.echo;

import io.netty.bootstrap.ServerBootstrap;

import io.netty.buffer.ByteBuf;

import io.netty.buffer.Unpooled;

import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelOption;

import io.netty.channel.EventLoopGroup;

import io.netty.channel.nio.NioEventLoopGroup;

import io.netty.channel.socket.SocketChannel;

import io.netty.channel.socket.nio.NioServerSocketChannel;

import io.netty.handler.codec.DelimiterBasedFrameDecoder;

import io.netty.handler.codec.string.StringDecoder;

import io.netty.handler.logging.LogLevel;

import io.netty.handler.logging.LoggingHandler;

public class EchoServer {

    public void bind(int port) throws Exception {

    // 配置服务端的NIO线程组

    EventLoopGroup bossGroup = new NioEventLoopGroup();

    EventLoopGroup workerGroup = new NioEventLoopGroup();

    try {

        ServerBootstrap b = new ServerBootstrap();

        b.group(bossGroup, workerGroup)

            .channel(NioServerSocketChannel.class)

            .option(ChannelOption.SO_BACKLOG, 100)

            .handler(new LoggingHandler(LogLevel.INFO))

            .childHandler(new ChannelInitializer<SocketChannel>() {

            @Override

            public void initChannel(SocketChannel ch)

                throws Exception {

                ByteBuf delimiter = Unpooled.copiedBuffer("$_".getBytes());

                ch.pipeline().addLast(new DelimiterBasedFrameDecoder(1024,delimiter));

                ch.pipeline().addLast(new StringDecoder());

                ch.pipeline().addLast(new EchoServerHandler());

            }

            });

        // 绑定端口，同步等待成功

        ChannelFuture f = b.bind(port).sync();

        // 等待服务端监听端口关闭

        f.channel().closeFuture().sync();

    } finally {

        // 优雅退出，释放线程池资源

        bossGroup.shutdownGracefully();

        workerGroup.shutdownGracefully();

    }

    }

    public static void main(String[] args) throws Exception {

    int port = 8080;

    if (args != null && args.length > 0) {

        try {

        port = Integer.valueOf(args[0]);

        } catch (NumberFormatException e) {

        // 采用默认值

        }

    }

    new EchoServer().bind(port);

    }

}

EchoServerHandler：服务器数据处理

/*

 * Copyright 2012 The Netty Project

 *

 * The Netty Project 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 nettyTcp01.echo;

import io.netty.buffer.ByteBuf;

import io.netty.buffer.Unpooled;

import io.netty.channel.ChannelHandler.Sharable;

import io.netty.channel.ChannelHandlerAdapter;

import io.netty.channel.ChannelHandlerContext;

@Sharable

public class EchoServerHandler extends ChannelHandlerAdapter {

    int counter = 0;

    @Override

    public void channelRead(ChannelHandlerContext ctx, Object msg)

        throws Exception {

    String responseBody = (String) msg;

    System.out.println("This is " + ++counter + " times receive client : ["+ responseBody + "]");

    responseBody += "$_";

    ByteBuf echo = Unpooled.copiedBuffer(responseBody.getBytes());

    ctx.writeAndFlush(echo);

    }

    @Override

    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {

    cause.printStackTrace();

    ctx.close();// 发生异常，关闭链路

    }

}
05-07 15:35
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