前言
WebSocket 使得客户端和服务器之间的数据交换变得更加简单，允许服务端主动向客户端推送数据。在WebSocket API 中，浏览器和服务器只需要完成一次握手，两者之间就直接可以创建持久性的连接，并进行双向数据传输。
Netty框架的优势
1.API使用简单，开发门槛低；
2.功能强大，预置了多种编解码功能，支持多种主流协议；
3.定制能力强，可以通过ChannelHandler对通信框架进行灵活地扩展；
4.性能高，通过与其他业界主流的NIO框架对比，Netty的综合性能最优；
5.成熟、稳定，Netty修复了已经发现的所有JDK NIO BUG，业务开发人员不需要再为NIO的BUG而烦恼
提示：以下是本篇文章正文内容，下面案例可供参考
一、引入netty依赖
二、使用步骤
1.引入基础配置类
package com.test.netty;
public enum Cmd {
START("000", "連接成功"),
WMESSAGE("001", "消息提醒"),
;
private String cmd;
private String desc;
Cmd(String cmd, String desc) {
this.cmd = cmd;
this.desc = desc;
}
public String getCmd() {
return cmd;
}
public String getDesc() {
return desc;
}
}
2.netty服务启动监听器
package com.test.netty;
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;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.ApplicationRunner;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
/**
- @author test
- 服務啟動監聽器
**/
@Slf4j
@Component
public class NettyServer {
@Value("${server.netty.port}")
private int port;
@Autowired
private ServerChannelInitializer serverChannelInitializer;
@Bean
ApplicationRunner nettyRunner() {
return args -> {
//new 一個主線程組
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
//new 一個工作線程組
EventLoopGroup workGroup = new NioEventLoopGroup();
ServerBootstrap bootstrap = new ServerBootstrap()
.group(bossGroup, workGroup)
.channel(NioServerSocketChannel.class)
.childHandler(serverChannelInitializer)
//設置隊列大小
.option(ChannelOption.SO_BACKLOG, 1024)
// 兩小時內沒有數據的通信時,TCP會自動發送一個活動探測數據報文
.childOption(ChannelOption.SO_KEEPALIVE, true);
//綁定端口,開始接收進來的連接
try {
ChannelFuture future = bootstrap.bind(port).sync();
log.info("服務器啟動開始監聽端口: {}", port);
future.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
//關閉主線程組
bossGroup.shutdownGracefully();
//關閉工作線程組
workGroup.shutdownGracefully();
}
};
}
}
3.netty服务端处理器
package com.test.netty;
import com.test.common.util.JsonUtil;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import java.net.URLDecoder;
import java.util.*;
/**
- @author test
- netty服務端處理器
**/
@Slf4j
@Component
@ChannelHandler.Sharable
public class NettyServerHandler extends SimpleChannelInboundHandler{
@Autowired
private ServerChannelCache cache;
private static final String dataKey = "test=";
@Data
public static class ChannelCache {
}
/**
- 客戶端連接會觸發
*/
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
Channel channel = ctx.channel();
log.info("通道連接已打開，ID->{}......", channel.id().asLongText());
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
if (evt instanceof WebSocketServerProtocolHandler.HandshakeComplete) {
Channel channel = ctx.channel();
WebSocketServerProtocolHandler.HandshakeComplete handshakeComplete = (WebSocketServerProtocolHandler.HandshakeComplete) evt;
String requestUri = handshakeComplete.requestUri();
requestUri = URLDecoder.decode(requestUri, "UTF-8");
log.info("HANDSHAKE_COMPLETE，ID->{}，URI->{}", channel.id().asLongText(), requestUri);
String socketKey = requestUri.substring(requestUri.lastIndexOf(dataKey) + dataKey.length());
if (socketKey.length() > 0) {
cache.add(socketKey, channel);
this.send(channel, Cmd.DOWN_START, null);
} else {
channel.disconnect();
ctx.close();
}
}
super.userEventTriggered(ctx, evt);
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
Channel channel = ctx.channel();
log.info("通道連接已斷開，ID->{}，用戶ID->{}......", channel.id().asLongText(), cache.getCacheId(channel));
cache.remove(channel);
}
/**
- 發生異常觸發
*/
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
Channel channel = ctx.channel();
log.error("連接出現異常，ID->{}，用戶ID->{}，異常->{}......", channel.id().asLongText(), cache.getCacheId(channel), cause.getMessage(), cause);
cache.remove(channel);
ctx.close();
}
/**
- 客戶端發消息會觸發
*/
@Override
protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
try {
// log.info("接收到客戶端發送的消息：{}", msg.text());
ctx.channel().writeAndFlush(new TextWebSocketFrame(JsonUtil.toString(Collections.singletonMap("cmd", "100"))));
} catch (Exception e) {
log.error("消息處理異常：{}", e.getMessage(), e);
}
}
public void send(Cmd cmd, String id, Object obj) {
HashMap
if (channels == null) {
return;
}
Map
data.put("cmd", cmd.getCmd());
data.put("data", obj);
String msg = JsonUtil.toString(data);
log.info("服務器下發消息: {}", msg);
channels.values().forEach(channel -> {
channel.writeAndFlush(new TextWebSocketFrame(msg));
});
}
public void send(Channel channel, Cmd cmd, Object obj) {
Map
data.put("cmd", cmd.getCmd());
data.put("data", obj);
String msg = JsonUtil.toString(data);
log.info("服務器下發消息: {}", msg);
channel.writeAndFlush(new TextWebSocketFrame(msg));
}
}
4.netty服务端缓存类
package com.test.netty;
import io.netty.channel.Channel;
import io.netty.util.AttributeKey;
import org.springframework.stereotype.Component;
import java.util.HashMap;
import java.util.concurrent.ConcurrentHashMap;
@Component
public class ServerChannelCache {
private static final ConcurrentHashMap
private static final AttributeKey
public String getCacheId(Channel channel) {
return channel.attr(CHANNEL_ATTR_KEY).get();
}
public void add(String cacheId, Channel channel) {
channel.attr(CHANNEL_ATTR_KEY).set(cacheId);
HashMap
if (hashMap == null) {
hashMap = new HashMap<>();
}
hashMap.put(channel.id().asShortText(), channel);
CACHE_MAP.put(cacheId, hashMap);
}
public HashMap
if (cacheId == null) {
return null;
}
return CACHE_MAP.get(cacheId);
}
public void remove(Channel channel) {
String cacheId = getCacheId(channel);
if (cacheId == null) {
return;
}
HashMap
if (hashMap == null) {
hashMap = new HashMap<>();
}
hashMap.remove(channel.id().asShortText());
CACHE_MAP.put(cacheId, hashMap);
}
}
5.netty服务初始化器
package com.test.netty;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
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.stream.ChunkedWriteHandler;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
- @author test
- netty服務初始化器
**/
@Component
public class ServerChannelInitializer extends ChannelInitializer{
@Autowired
private NettyServerHandler nettyServerHandler;
@Override
protected void initChannel(SocketChannel socketChannel) throws Exception {
ChannelPipeline pipeline = socketChannel.pipeline();
pipeline.addLast(new HttpServerCodec());
pipeline.addLast(new ChunkedWriteHandler());
pipeline.addLast(new HttpObjectAggregator(8192));
pipeline.addLast(new WebSocketServerProtocolHandler("/test.io", true, 5000));
pipeline.addLast(nettyServerHandler);
}
}
6.html测试
7.vue测试
mounted() {
this.initWebsocket();
},
methods: {
initWebsocket() {
let websocket = new WebSocket('ws://localhost:port/test.io?test=123456');
websocket.onmessage = (event) => {
let msg = JSON.parse(event.data);
switch (msg.cmd) {
case "000":
this.message.warning("收到一條新的信息，請及時查看！")
break;
}
}
websocket.onclose = () => {
setTimeout(()=>{
this.initWebsocket();
},301000);
}
websocket.onerror = () => {
setTimeout(()=>{
this.initWebsocket();
},301000);
}
},
},
8.服务器下发消息
@Autowired
private NettyServerHandler nettyServerHandler;
nettyServerHandler.send(CmdWeb.WMESSAGE, id, message);
到此这篇关于Springboot+Netty+Websocket实现消息推送实例的文章就介绍到这了希望大家以后多多支持