Netty保姆级入门教程
2022-06-27 本文已影响0人
醉鱼java
今天是实战篇，没有理论，只是记录一下使用Netty搭建一个本地服务，实现客户端数据发送到服务端数据Demo的教程，理论篇以及更深层次学习Netty可以点个关注，保证后续更新不错过！！！
搭建Netty服务端
服务端
使用main方法的形式构建，启动在本地8888端口
package com.zuiyu.netty;
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 @醉鱼
* @link https://github.com/TianPuJun
* @ClassName NettyService
* @Description
* @Date 22:05 2022/6/28
**/
public class NettyService {
public static void main(String[] args) throws InterruptedException {
// 用于接收客户端链接的线程工作组
EventLoopGroup eventLoopGroup = new NioEventLoopGroup();
// 用于接收客户端链接读写操作的线程组
EventLoopGroup workGroup = new NioEventLoopGroup();
// 辅助类，帮助创建netty服务
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap
// 绑定两个工作组
.group(eventLoopGroup,workGroup)
// 设置nio 模式
.channel(NioServerSocketChannel.class)
// option 针对服务器端配置，childOption 针对客户端链接通道配置
// 设置tcp 缓冲区
.option(ChannelOption.SO_BACKLOG,1024)
// 设置发送数据的缓存大小
.childOption(ChannelOption.SO_SNDBUF,32*1024)
// 设置读取数据的缓存大小
.childOption(ChannelOption.SO_RCVBUF,32*1024)
// 设置保持长链接
.childOption(ChannelOption.SO_KEEPALIVE,true)
// 初始化绑定服务通道
.childHandler(new ChannelInitializer<SocketChannel>() {
protected void initChannel(SocketChannel socketChannel) throws Exception {
// 为通道进行初始化，数据传输过来的适合会进行拦截和执行(可以有多个拦截器)
socketChannel.pipeline().addLast(new ServerHandler());
}
});
ChannelFuture sync = serverBootstrap.bind(8888).sync();
// 释放链接
sync.channel().closeFuture().sync();
workGroup.shutdownGracefully();
eventLoopGroup.shutdownGracefully();
}
}
服务端监听
新建ServerHandler监听数据
package com.zuiyu.netty;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.ReferenceCountUtil;
import java.util.logging.Logger;
/**
* @author @醉鱼
* @link https://github.com/TianPuJun
* @ClassName ServerHandler
* @Description 服务回调
* @Date 22:15 2022/6/28
**/
public class ServerHandler extends ChannelInboundHandlerAdapter {
public static final Logger LOGGER = Logger.getLogger("ServerHandler");
public ServerHandler() {
super();
}
@Override
public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
super.channelRegistered(ctx);
}
@Override
public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
super.channelUnregistered(ctx);
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
LOGGER.info("======服务端通道激活======");
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
super.channelInactive(ctx);
}
/**
* 当通道有数据读取时的监听
* @param ctx
* @param msg
* @throws Exception
*/
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
try {
// 传输buffer 对象
ByteBuf buf = (ByteBuf)msg;
// 定义byte数组
byte[] req =new byte[buf.readableBytes()];
// 从缓冲区获取数据到req
buf.readBytes(req);
// 读取数据转为字符串
String body = new String(req,"utf-8");
LOGGER.info("服务端读取的数据："+body);
// 响应给客户端的数据
ctx.writeAndFlush(Unpooled.copiedBuffer("netty server response data: you are beautiful".getBytes()))
// 添加addListener可以触发关闭通道监听事件，客户端短链接场景使用
// .addListener(ChannelFutureListener.CLOSE);
;
}catch (Exception e){
e.printStackTrace();
}finally {
ReferenceCountUtil.release(msg);
}
}
/**
* 当我们读取完成数据时触发的操作
* @param ctx
* @throws Exception
*/
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
LOGGER.info("====== 服务端数据读取完成 ======");
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
super.userEventTriggered(ctx, evt);
}
@Override
public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception {
super.channelWritabilityChanged(ctx);
}
/**
* 当我们读取数据异常的时候触发的监听
* @param ctx
* @param cause
* @throws Exception
*/
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
LOGGER.info("====== 服务端数据读取异常 ======");
LOGGER.info(cause.getMessage());
ctx.close();
}
}
搭建Netty客户端
客户端
同样适用main方法的形式搭建测试，发送数据到本地8888端口
package com.zuiyu.netty;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
/**
* @author @醉鱼
* @link https://github.com/TianPuJun
* @ClassName NettyClient
* @Description
* @Date 22:27 2022/6/28
**/
public class NettyClient {
public static void main(String[] args) throws InterruptedException {
NioEventLoopGroup eventExecutors = new NioEventLoopGroup();
Bootstrap b = new Bootstrap();
b.group(eventExecutors)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<SocketChannel>() {
protected void initChannel(SocketChannel socketChannel) throws Exception {
socketChannel.pipeline().addLast(new ClientHandler());
}
});
ChannelFuture channelFuture = b.connect("127.0.0.1", 8888).syncUninterruptibly();
channelFuture.channel().writeAndFlush(Unpooled.copiedBuffer("netty 客户端请求数据:zuiyu netty 服务发送数据测试".getBytes()));
// 释放链接
channelFuture.channel().closeFuture().sync();
}
}
客户端监听
新建客户端监听ClientHandler，发送数据时打印数据
package com.zuiyu.netty;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.ReferenceCountUtil;
import java.util.logging.Logger;
/**
* @author @醉鱼
* @link https://github.com/TianPuJun
* @ClassName ClientHandler
* @Description
* @Date 22:32 2022/6/28
**/
public class ClientHandler extends ChannelInboundHandlerAdapter {
public static final Logger LOGGER = Logger.getLogger("ClientHandler");
public ClientHandler() {
super();
}
@Override
public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
super.channelRegistered(ctx);
}
@Override
public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
super.channelUnregistered(ctx);
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
LOGGER.info("====== 客户端通道激活======");
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
super.channelInactive(ctx);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
try {
// 传输buffer 对象
ByteBuf buf = (ByteBuf)msg;
// 定义byte数组
byte[] req =new byte[buf.readableBytes()];
// 从缓冲区获取数据到req
buf.readBytes(req);
// 读取数据转为字符串
String body = new String(req,"utf-8");
LOGGER.info("客户端读取的数据："+body);
}catch (Exception e){
e.printStackTrace();
}finally {
ReferenceCountUtil.release(msg);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
LOGGER.info("====== 客户端读取数据完毕======");
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
super.userEventTriggered(ctx, evt);
}
@Override
public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception {
super.channelWritabilityChanged(ctx);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
LOGGER.info("====== 客户端读取数据异常======");
ctx.close();
}
}
验证打印输出
-
先启动
NettyServer#main -
再启动
NettyClient#main -
结果如下
Demo 教程到此结束，只为记录过程，代码详细位置NettyServer中都有注释，觉得有帮助动动小手点个关注再走哦，点关注不迷路
Demo 地址 :
https://github.com/TianPuJun/spring-notes/tree/master/netty
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