Spring boot + Websocket 初篇

dependencies {   compile('org.springframework.boot:spring-boot-starter-security')  compile('org.springframework.boot:spring-boot-starter-thymeleaf')  compile('org.springframework.boot:spring-boot-starter-websocket')  compile('org.thymeleaf.extras:thymeleaf-extras-springsecurity4')  compile('org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.0')  runtime('mysql:mysql-connector-java')  compile('org.springframework.boot:spring-boot-devtools')}

package com.demo.entity;import com.demo.mapper.CollectorMapper;import org.springframework.web.socket.TextMessage;import org.springframework.web.socket.WebSocketSession;import java.io.IOException;import java.util.List;import java.util.TimerTask;// 定时从数据库中捞数据public class TimerDBTask extends TimerTask {    private WebSocketSession socketSession;    private CollectorMapper collectorMapper;    private int total = 0;    @Override    public void run() {        int latest = collectorMapper.countTotal();        if(latest > total){            List<CollectData> dataList = collectorMapper.getCollectedValues();            StringBuilder initial = new StringBuilder();            for(CollectData collectData: dataList){                initial.append(collectData.toString());                initial.append("|");            }            if(initial.length() > 1) {                initial.deleteCharAt(initial.length() - 1);            }            total = latest;            try {                socketSession.sendMessage(new TextMessage(initial.toString()));            } catch (IOException e) {                e.printStackTrace();            }        }    }    public TimerDBTask(WebSocketSession session, CollectorMapper collectorMapper){        this.socketSession = session;        this.collectorMapper = collectorMapper;    }}

package com.demo.config;import com.demo.entity.MessageHandler;import com.demo.mapper.CollectorMapper;import org.springframework.beans.factory.annotation.Autowired;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;@Configuration@EnableWebSocketpublic class WebsocketConfig implements WebSocketConfigurer{    @Autowired    private CollectorMapper collectorMapper;    @Override    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {        registry.addHandler(messageHandler(), "/websocket-endpoint");    }    @Bean    public WebSocketHandler messageHandler(){        return new MessageHandler(this.collectorMapper);    }}

package com.demo.entity;import com.demo.mapper.CollectorMapper;import org.springframework.web.socket.CloseStatus;import org.springframework.web.socket.TextMessage;import org.springframework.web.socket.WebSocketMessage;import org.springframework.web.socket.WebSocketSession;import org.springframework.web.socket.handler.TextWebSocketHandler;import java.util.Timer;public class MessageHandler extends TextWebSocketHandler {    private Timer timer;    private CollectorMapper collectorMapper;    public MessageHandler(){    }    public MessageHandler(CollectorMapper collectorMapper){        this.collectorMapper = collectorMapper;    }    @Override    public void afterConnectionEstablished(WebSocketSession session) throws Exception {        // The websocket has been opened        // might save this session object so that can send messages to it outside of this method        String loginUser = session.getPrincipal().getName();        timer = new Timer(true);        long delay = 0l;        TimerDBTask dbTask = new TimerDBTask(session, collectorMapper);        timer.schedule(dbTask, delay, 60000);//        session.sendMessage(new TextMessage("You're now connected to the server.This is the first message."));    }    @Override    public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {        super.handleMessage(session, message);    }    @Override    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {        // a message has been received        System.out.println("Message received:" + message.getPayload());        if(!session.isOpen()){            timer.cancel();            return;        }        super.handleTextMessage(session, message);    }    @Override    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {        super.afterConnectionClosed(session, status);        // The websocket has been closed    }}