HelloWorld
客户端通向服务器端发送消息，服务器端读取数据（你好）并且返回（new Date()），客户端读取数据
pom
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>5.0.0.Alpha1</version>
</dependency>TimeServerHandler
服务器端读取数据并且回应请求，继承ChannelHandlerAdapter并且实现channelRead和exceptionCaught方法
package myhelloworld;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import java.util.Date;
/**
* @author CBeann
* @create 2019-08-27 18:31
*/
public class TimeServerHandler extends ChannelHandlerAdapter {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
//服务器读客户端发送来的数据
ByteBuf buf = (ByteBuf) msg;
byte[] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String body = new String(req, "UTF-8");
System.out.println("The TimeServer receive :" + body);
//服务器向客户端回应请求
ByteBuf response = Unpooled.copiedBuffer(new Date().toString().getBytes());
ctx.writeAndFlush(response);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.close();
}
//
}
TimeServer
package myhelloworld;
import io.netty.bootstrap.ServerBootstrap;
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;
/**
* @author CBeann
* @create 2019-08-27 18:22
*/
public class TimeServer {
public static void main(String[] args) throws Exception {
int port = 8080;
//配置服务器端的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, 1024)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel socketChannel) throws Exception {
//TimeClientHandler是自己定义的方法
socketChannel.pipeline().addLast(new TimeServerHandler());
}
});
//绑定端口
ChannelFuture f = b.bind(port).sync();
//等待服务端监听端口关闭
f.channel().closeFuture().sync();
} catch (Exception e) {
} finally {
//优雅关闭，释放线程池资源
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
启动NettyServer的模版代码
private void bing(int port) {
EventLoopGroup parentGroup = new NioEventLoopGroup();
EventLoopGroup childGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(parentGroup, childGroup)
.channel(NioServerSocketChannel.class) //非阻塞模式
.option(ChannelOption.SO_BACKLOG, 128)
.childHandler(new MyChannelInitializer());
ChannelFuture f = b.bind(port).sync();
System.out.println("itstack-demo-netty server start done. {关注公众号：bugstack虫洞栈，获取源码}");
f.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
childGroup.shutdownGracefully();
parentGroup.shutdownGracefully();
}
}TimeClientHandler
客户端读取服务器响应数据，继承ChannelHandlerAdapter并且实现channelRead和exceptionCaught方法
package myhelloworld;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.ReferenceCountUtil;
/**
* @author CBeann
* @create 2019-08-27 18:47
*/
public class TimeClientHandler extends ChannelHandlerAdapter {
//客户端读取服务器发送的数据
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
try {
ByteBuf buf = (ByteBuf) msg;
byte[] req = new byte[buf.readableBytes()];
buf.readBytes(req);
String body = new String(req, "UTF-8");
System.out.println("Now is:" + body);
} catch (Exception e) {
} finally {
//标配
ReferenceCountUtil.release(msg);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.close();
}
}
TimeClient
package myhelloworld;
import io.netty.bootstrap.Bootstrap;
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;
/**
* @author CBeann
* @create 2019-08-27 18:43
*/
public class TimeClient {
public static void main(String[] args) throws Exception {
int port = 8080;
String host = "127.0.0.1";
//配置客户端NIO线程组
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel socketChannel) throws Exception {
//TimeClientHandler是自己定义的方法
socketChannel.pipeline().addLast(new TimeClientHandler());
}
});
//发起异步连接操作
ChannelFuture f = b.connect(host, port).sync();
//发送数据
f.channel().writeAndFlush(Unpooled.copiedBuffer("您好".getBytes()));
//Thread.sleep(1000);//防止TCP粘包
//f.channel().writeAndFlush(Unpooled.copiedBuffer("您好".getBytes()));
//Thread.sleep(1000);
//f.channel().writeAndFlush(Unpooled.copiedBuffer("您好".getBytes()));
//Thread.sleep(1000);
//等待客户端链路关闭
f.channel().closeFuture().sync();
} catch (Exception e) {
} finally {
//优雅关闭
group.shutdownGracefully();
}
}
}
学习总结
1）自己敲一遍，因为不确定你查询到的博客是对还是错的
2）很多地方都是固定格式，需要修改的地方就那么几个
2.1）option(ChannelOption.SO_BACKLOG, 1024) 修改一些参数
2.2）socketChannel.pipeline().addLast(new TimeServerHandler())添加一些自己定义或者系统的handler
2.3）自己定义的handler
3）请坚持
