这是我参与2022首次更文挑战的第28天，活动详情查看：2022首次更文挑战
简介
使用spring boot 提供的websocket搭建websocket服务器，其中主要的有下面的三个部分：配置、通信处理、拦截器
- WebSocketConfigurer:websocket相关配置，主要配置其入口、消息处理类、拦截器
- WebSocketHandler：处理相关的通信，连接的建立、消息的发送、错误的处理，大部分的代码写在这里
- HandshakeInterceptor ：拦截器，可以使用默认的HttpSessionHandshakeInterceptor()即可
Maven相关导入
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>visual</artifactId>
<version>0.0.1-SNAPSHOT</version>
<!-- Inherit defaults from Spring Boot -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.0.BUILD-SNAPSHOT</version>
</parent>
<!-- Add typical dependencies for a web application -->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- websocket -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<!-- 用于测试的依赖项 -->
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>1.9.5</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<!-- Package as an executable jar -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<!-- Add Spring repositories -->
<!-- (you don't need this if you are using a .RELEASE versio
n) -->
<repositories>
<repository>
<id>spring-snapshots</id>
<url>http://repo.spring.io/snapshot</url>
<snapshots><enabled>true</enabled></snapshots>
</repository>
<repository>
<id>spring-milestones</id>
<url>http://repo.spring.io/milestone</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-snapshots</id>
<url>http://repo.spring.io/snapshot</url>
</pluginRepository>
<pluginRepository>
<id>spring-milestones</id>
<url>http://repo.spring.io/milestone</url>
</pluginRepository>
</pluginRepositories>
</project>
主类编写
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
// SpringBootApplication 这个注入表示整个工程的入口
@SpringBootApplication
public class Main {
public static void main(String[] args) {
// 设置服务的监听端口
System.getProperties().put( "server.port", 8000);
SpringApplication.run(Main.class, args);
}
}
WebSocketHandler 消息处理类编写
import org.springframework.web.socket.*;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
/**
* websocket的处理程序
*/
public class SafetyAttackHandler implements WebSocketHandler{
// 用于保存所有连接的客户端信息
private static Map<WebSocketSession, Map> clients = new HashMap<WebSocketSession, Map>();
/**
* 连接成功后的操作
* 连接成功建立以后添加客户端信息
* @param webSocketSession
* @throws Exception
*/
@Override
public void afterConnectionEstablished(WebSocketSession webSocketSession) throws Exception {
webSocketSession.sendMessage(new TextMessage("Connect successful"));
clients.put(webSocketSession, new HashMap());
}
/**
* 收到消息后的处理
* @param webSocketSession
* @param webSocketMessage
* @throws Exception
*/
@Override
public void handleMessage(WebSocketSession webSocketSession, WebSocketMessage<?> webSocketMessage) throws Exception {
}
/**
* 发生错误后的处理
* 移除相应的客户端信息
* @param webSocketSession
* @param throwable
* @throws Exception
*/
@Override
public void handleTransportError(WebSocketSession webSocketSession, Throwable throwable) throws Exception {
clients.remove(webSocketSession);
webSocketSession.sendMessage(new TextMessage(throwable.toString()));
}
/**
* 连接关闭时的处理
* 移除关闭的客户端
* @param webSocketSession
* @param closeStatus
* @throws Exception
*/
@Override
public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {
clients.remove(webSocketSession);
webSocketSession.sendMessage(new TextMessage("Close connect"));
}
@Override
public boolean supportsPartialMessages() {
return false;
}
/**
* 推送消息到所有的客户端
* @param message
*/
public static void sendMessageToAll(String message) {
for(WebSocketSession session : clients.keySet()) {
try {
session.sendMessage(new TextMessage(message));
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
WebSocketConfigurer 配置编写
import cn.nssas.eelantech.handlers.SafetyAttackHandler;
import org.springframework.context.annotation.Bean;
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;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
/**
* websocket接口配置
*/
@Configuration
@EnableWebSocket
public class SafetyAttackWebSocket implements WebSocketConfigurer {
/**
* 设置连接的路由、处理相关类
* addHandler：设置websocket的处理类和相应接口URL："/safetyAttackWebsocket"
* setAllowedOrigins：设置链接允许，*代码允许所有情况，需要进行此设置，不然可能导致连接失败
* @param webSocketHandlerRegistry
*/
@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry webSocketHandlerRegistry) {
webSocketHandlerRegistry.addHandler(myHandler(), "/safetyAttackWebsocket").addInterceptors(new HttpSessionHandshakeInterceptor()).setAllowedOrigins("*");
}
/**
* 返回websocket连接对应处理类
* @return
*/
@Bean
public WebSocketHandler myHandler() {
return new SafetyAttackHandler();
}
}
测试连接
- 可以使用页面的测试
- 输入：ws://127.0.0.1:8000/safetyAttackWebsocke，进行连接即可
