Netty5中使用LineBasedFrameDecoder解决TCP粘包问题

/**
*
*/
package upup.me.netty.practice02;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

/**
* @author Administrator
*
*/
public class TimeServer {

public void bind(int port) {
// 配置服务端的NIO线程组
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();

// 设置线程组及Socket参数
b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).option(ChannelOption.SO_BACKLOG, 1024)
.childHandler(new ChildChannelHandler());

// 绑定端口，同步等待成功
ChannelFuture f = b.bind(port).sync();
System.out.println("服务已经启动,端口:" + port);

f.channel().closeFuture().sync();
} catch (Exception e) {
} finally {
// 退出释放线程池资源
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
System.out.println("服务销毁!");
}
}

public static void main(String[] args) {
int port = 8080;
if (null != args && args.length > 0) {
try {
port = Integer.valueOf(args[0]);
} catch (Exception e) {
// 采用默认值
}
}
new TimeServer().bind(port);
}

}

/**
*
*/
package upup.me.netty.practice02;

import java.util.Date;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

/**
* @author Administrator
*
*/
public class TimeServerHandler extends ChannelHandlerAdapter {

private int counter;

public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
String body = (String) msg;
System.out.println("The time server receive order:" + body + ";the counter is:" + (++counter));
String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body) ? new Date(System.currentTimeMillis()).toString()
: "BAD ORDER";
currentTime = currentTime + System.getProperty("line.separator");
ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes());
ctx.write(resp);
}

public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}

public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
ctx.close();
}

}

/**
*
*/
package upup.me.netty.practice02;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

/**
* @author Administrator
*
*/
public class ChildChannelHandler extends ChannelInitializer<SocketChannel> {

@Override
protected void initChannel(SocketChannel ch) throws Exception {
// 以下两行代码为了解决半包读问题
ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
ch.pipeline().addLast(new StringDecoder());

ch.pipeline().addLast(new TimeServerHandler());
}

}

/**
*
*/
package upup.me.netty.practice02;

import io.netty.bootstrap.Bootstrap;
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.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

/**
* @author Administrator
*
*/
public class TimeClient {

public void connect(int port, String host) {
// 配置客户端的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 {
// 以下两行代码为了解决半包读问题
ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
ch.pipeline().addLast(new StringDecoder());

ch.pipeline().addLast(new TimeClientHandler());
}
});
// 发起异步连接操作
ChannelFuture f = b.connect(host, port).sync();

// 等待链路关闭
f.channel().closeFuture().sync();

} catch (Exception e) {
} finally {
// 退出，释放NIO线程组
group.shutdownGracefully();
}
}

publi
ac12
c static void main(String[] args) {
int port = 8080;
if (null != args && args.length > 0) {
try {
port = Integer.valueOf(args[0]);
} catch (Exception e) {
}
}
new TimeClient().connect(port, "127.0.0.1");
}
}

/**
*
*/
package upup.me.netty.practice02;

import java.io.UnsupportedEncodingException;
import java.util.logging.Logger;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

/**
* @author Administrator
*
*/
public class TimeClientHandler extends ChannelHandlerAdapter {

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

private int counter;

private byte[] req;

public TimeClientHandler() {
req = ("QUERY TIME ORDER" + System.getProperty("line.separator")).getBytes();
}

public void channelActive(ChannelHandlerContext ctx) {
ByteBuf message = null;
for (int i = 0; i < 100; i++) {
message = Unpooled.buffer(req.length);
message.writeBytes(req);
ctx.writeAndFlush(message);
}
}

public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
String body = (String) msg;
System.out.println("Now is:" + body + "; the counter is:" + (++counter));
}

public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
logger.warning("Unexcepted exception from downstream:" + cause.getMessage());
ctx.close();
}

}