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邢台建网站,金华网站制作系统,北京市保障房建设官方网站,嘉兴做网站Netty介绍在文章末尾 Netty介绍项目背景传统socket通信，有需要自身管理整个状态，业务繁杂等问题。 pom.xml <dependency><groupId>io.netty</groupId><artifactId>netty-all</artifactId><version>4.1.117.F…

Netty介绍在文章末尾 Netty介绍

项目背景

传统socket通信，有需要自身管理整个状态，业务繁杂等问题。

pom.xml

<dependency><groupId>io.netty</groupId><artifactId>netty-all</artifactId><version>4.1.117.Final</version>
</dependency>

代码

封装Netty的服务类

package com.example.server;import com.example.exception.ServiceException;
import com.example.handler.NettyServerInitializer;
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;
import lombok.extern.slf4j.Slf4j;@Slf4j
public class NettyServer {// 用于处理连接请求的线程组private EventLoopGroup bossGroup;// 用于处理I/O操作的线程组private EventLoopGroup workerGroup;// 服务器private ChannelFuture channelFuture;/*** 启动 Netty 服务端** @param port 监听的端口*/public void start(int port) {bossGroup = new NioEventLoopGroup(); // 初始化bossGroupworkerGroup = new NioEventLoopGroup(); // 初始化workerGrouptry {ServerBootstrap bootstrap = new ServerBootstrap();bootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class) // 使用NIO传输.childHandler(new ChannelInitializer<SocketChannel>() {@Overrideprotected void initChannel(SocketChannel ch) {// 添加编解码器和处理器ch.pipeline().addLast(new NettyServerInitializer());}}).option(ChannelOption.SO_BACKLOG, 128) // 设置TCP参数.childOption(ChannelOption.SO_KEEPALIVE, true);// 绑定端口并启动服务器channelFuture = bootstrap.bind(port).sync();log.info("Netty 服务端启动成功，监听端口: {}", port);} catch (InterruptedException e) {log.error("Netty 服务端启动失败，端口: {}, 异常: {}", port, e.getMessage(), e);throw new ServiceException("Netty 服务端启动异常");} catch (Exception e) {log.error("绑定端口时发生异常: {}", e.getMessage(), e);throw new ServiceException("端口绑定异常");}}/*** 停止 Netty 服务端*/public void stop() {if (channelFuture != null) {channelFuture.channel().close();}if (bossGroup != null) {bossGroup.shutdownGracefully();}if (workerGroup != null) {workerGroup.shutdownGracefully();}System.out.println("Netty 服务端已关闭");}}

封装Netty服务的管理类

用来创建和销毁多个Netty

package com.example.server;import com.example.exception.ServiceException;
import org.springframework.stereotype.Service;import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;@Service
public class NettyServerManager {private final ConcurrentHashMap<Integer, NettyServer> nettyServers = new ConcurrentHashMap<>();/*** 启动 Netty 服务端** @param port 监听的端口*/public void startNettyServer(int port) {if (nettyServers.containsKey(port)) {throw new ServiceException("端口 " + port + " 已被占用");}NettyServer nettyServer = new NettyServer();nettyServer.start(port);nettyServers.put(port, nettyServer);}/*** 停止 Netty 服务端** @param port 监听的端口*/public void stopNettyServer(int port) {NettyServer nettyServer = nettyServers.get(port);if (nettyServer != null) {nettyServer.stop();nettyServers.remove(port);}}/*** 获取所有 Netty 服务端实例*/public Map<Integer, NettyServer> getNettyServers() {return nettyServers;}
}

NettyServer的初始化

package com.example.handler;import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;public class NettyServerInitializer extends ChannelInitializer<SocketChannel> {@Overrideprotected void initChannel(SocketChannel ch) {ch.pipeline()// HTTP 编解码器：支持 HTTP 请求和响应.addLast(new HttpServerCodec())// 聚合 HTTP 消息，避免处理分块的 HTTP 请求.addLast(new HttpObjectAggregator(65536))// WebSocket 协议处理器，确保路径 `/websocket` 处理 WebSocket 握手和控制帧.addLast(new WebSocketServerProtocolHandler("/websocket"))// 字符串解码器，将字节流解析为字符串.addLast(new StringDecoder(CharsetUtil.UTF_8))// 字符串编码器，将字符串转换为字节流.addLast(new StringEncoder(CharsetUtil.UTF_8))// 自定义消息处理器，用于处理业务逻辑.addLast(new WebSocketFrameHandler());}
}

handler处理器类

用来处理具体的消息

package com.example.handler;import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;@Slf4j
@Component
public class WebSocketFrameHandler extends ChannelInboundHandlerAdapter {@Resourceprivate UserService userService;@PostConstructpublic void init() {webSocketFrameHandler = this;}/*** 当 Channel 变为活跃状态（连接建立）时调用*/@Overridepublic void channelActive(ChannelHandlerContext ctx) throws Exception {log.warn("{} 已连接", ctx.channel().remoteAddress());}/*** 当 Channel 变为不活跃状态（连接关闭）时调用*/@Overridepublic void channelInactive(ChannelHandlerContext ctx) {log.warn("{} 已断开", ctx.channel().remoteAddress());}/*** 当从 Channel 中读取到数据时调用*/@Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {}/*** 当一次数据读取完成时调用*/@Overridepublic void channelReadComplete(ChannelHandlerContext ctx) throws Exception {// log.info("Channel 数据读取完成");ctx.flush();}/*** 当处理过程中发生异常时调用*/@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {log.error("处理过程中发生异常，连接关闭: {}", cause.getMessage(), cause);ctx.close();}
}