Websocket

websocket主要可以分为服务器端和客户端两部分，其中服务器端又可以分为配置和服务

需要的依赖

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <!--以下两项需要如果不配置，解析themleaft 会有问题-->
        <thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
        <thymeleaf-layout-dialect.version>2.0.5</thymeleaf-layout-dialect.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
            <scope>runtime</scope>
        </dependency>
        <!--添加对websocket的支持-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>
        <!--添加对html的支持-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <version>1.5.6.RELEASE</version>
            <optional>true</optional>
            <scope>runtime</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>com.spotify</groupId>
                <artifactId>docker-maven-plugin</artifactId>
                <version>1.0.0</version>
                <configuration>
                    <imageName>suyu/${project.artifactId}:${project.version}</imageName>
                    <baseImage>java:8</baseImage>
                    <entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
                    <resources>
                        <resource>
                            <targetPath>/</targetPath>
                            <directory>${project.build.directory}</directory>
                            <include>${project.build.finalName}.jar</include>
                        </resource>
                    </resources>
                </configuration>
            </plugin>
        </plugins>
    </build>

后端配置

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

@Configuration  
public class WebSocketConfig {  
    @Bean  
    public ServerEndpointExporter serverEndpointExporter(){  
        return new ServerEndpointExporter();  
    }  
}  

后端服务

import org.springframework.stereotype.Component;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import java.util.concurrent.CopyOnWriteArraySet;

@Component
@ServerEndpoint("/webSocket")
//@Slf4j
public class WebSocket {
    private Session session;
    private static CopyOnWriteArraySet<WebSocket> webSocketSet = new CopyOnWriteArraySet<>();

    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        webSocketSet.add(this);
        System.out.println("【websocket消息】：打开连接" + webSocketSet.size());
    }

    @OnClose
    public void OnClose() {
        webSocketSet.remove(this);
        System.out.println("【websocket消息】：关闭连接" + webSocketSet.size());
    }

    @OnMessage
    public void OnMessage(String message) {
        System.out.println("【websocket消息】：接收到的消息" + message);
    }

    public void sendMessage(String message) {
        for (WebSocket webSocket : webSocketSet) {
            System.out.println("【websocket消息】：广播的消息" + message);
            try {
                webSocket.session.getBasicRemote().sendText(message);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

前端界面

<!DOCTYPE HTML>
<html>
<head>
    <title>WebSocket测试</title>
</head>
<body>
<h1>WebSocket测试</h1>
</body>
<script type="text/javascript">
    var websocket = null;
    if (!!window.WebSocket && window.WebSocket.prototype.send) {
        console.log("当前浏览器支持websocket");
        websocket=new WebSocket('ws://127.0.0.1:8086/webSocket');
    }else {
        console.log("当前浏览器不支持websocket");
    }
    websocket.onopen=function (evnet) {
        console.log("建立连接");
    }
    websocket.onclose=function (event) {
        console.log("关闭连接");
    }
    websocket.onmessage=function (event) {
        console.log("收到消息："+event.data);
    }
    websocket.onerror=function (event){
        console.log("连接错误");
    }

</script>
</html>

定时任务

使用springboot添加定时任务向前端发送信息

import com.zhang.websocket.server.WebSocket;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;


@Component
public class scheduled {
    WebSocket webSocket=new WebSocket();
    @Scheduled(fixedRate = 1000)
    public void pushDataScheduled(){
        webSocket.sendMessage("你好啊");
    }
}

注：添加定时任务需要在spring启动类前加入注解

@EnableScheduling//定时任务

效果图