之前做的需求都是客户端请求服务器响应,新需求是服务器主动推送信息到客户端.百度之后有流、长轮询、websoket等方式进行.但是目前更加推崇且合理的显然是websocket.
从springboot官网翻译了一些资料,再加上百度简单实现了springboot使用websocekt与客户端的双工通信.
1.首先搭建一个简单的springboot环境
<!-- Inherit defaults from Spring Boot -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
</parent>
<!-- Add typical dependencies for a web application -->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>2.引入springboot整合websocket依赖
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-websocket -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
<version>2.0.4.RELEASE</version>
</dependency>3.创建启动springboot的核心类
package com;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class GlobalConfig {
public static void main(String[] args) {
SpringApplication.run(GlobalConfig.class, args);
}
}4.创建websocket服务器
正如springboot 官网推荐的websocket案例,需要实现WebSocketHandler或者继承TextWebSocketHandler/BinaryWebSocketHandler当中的任意一个.
package com.xiaoer.handler;
import com.alibaba.fastjson.JSONObject;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;
import java.util.HashMap;
import java.util.Map;
/**
* 相当于controller的处理器
*/
public class MyHandler extends TextWebSocketHandler {
@Override
protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
String payload = message.getPayload();
Map<String, String> map = JSONObject.parseObject(payload, HashMap.class);
System.out.println("=====接受到的数据"+map);
session.sendMessage(new TextMessage("服务器返回收到的信息," + payload));
}
}5.注册处理器
package com.xiaoer.config;
import com.xiaoer.handler.MyHandler;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(myHandler(), "myHandler/{ID}");
}
public WebSocketHandler myHandler() {
return new MyHandler();
}
}6.运行访问
出现如上图是因为不能直接通过http协议访问,需要通过html5的ws://协议进行访问.
7.创建Html5 客户端
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<body>
<input id="text" type="text" />
<button onclick="send()">Send</button>
<button onclick="closeWebSocket()">Close</button>
<div id="message">
</div>
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script>
var userID="888";
var websocket=null;
$(function(){
connectWebSocket();
})
//建立WebSocket连接
function connectWebSocket(){
console.log("开始...");
//建立webSocket连接
websocket = new WebSocket("ws://127.0.0.1:8080/myHandler/ID="+userID);
//打开webSokcet连接时，回调该函数
websocket.onopen = function () {
console.log("onpen");
}
//关闭webSocket连接时，回调该函数
websocket.onclose = function () {
//关闭连接
console.log("onclose");
}
//接收信息
websocket.onmessage = function (msg) {
console.log(msg.data);
}
}
//发送消息
function send(){
var postValue={};
postValue.id=userID;
postValue.message=$("#text").val();
websocket.send(JSON.stringify(postValue));
}
//关闭连接
function closeWebSocket(){
if(websocket != null) {
websocket.close();
}
}
</script>
</body>
</html>8.运行
利用客户端运行之后仍然会出现上图中的一连接就中断了websocket连接.
这是因为spring默认不接受跨域访问:
As of Spring Framework 4.1.5, the default behavior for WebSocket and SockJS is to accept only same origin requests.需要在WebSocketConfig中设置setAllowedOrigins.
package com.xiaoer.config;
import com.xiaoer.handler.MyHandler;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(myHandler(), "myHandler/{ID}")
.setAllowedOrigins("*");
}
public WebSocketHandler myHandler() {
return new MyHandler();
}
}如下图,并未输出中断,说明连接成功.
9.服务器和客户端的相互通信
服务器端收到消息
客户端收到服务器主动推送消息
以上就是一个最基础的springboot简单应用.还可以通过拦截器、重写WebSocketConfigurer中的方法进行更为复杂的属性操作.具体可以参考SpringBoot集成WebSocket【基于纯H5】进行点对点[一对一]和广播[一对多]实时推送
html5
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