websocke连接

 
        
            org.springframework.boot
            spring-boot-starter-websocket
        

前端代码

    
        
        
    
    
        
        Send    
        Close
        

        
        
        
    

后端代码

**
 * 注册处理类及握手接口
 * 这个有两种方式：
 * 1.创建一个类来实现注册
 * 2.使用xml配置文件实现
 *
 * @author lhb
 */
@Configuration
@EnableWebSocket
public class SpringWebSocketConfig implements WebSocketConfigurer {
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        //前台 可以使用websocket环境
        registry.addHandler(myHandler(), "websocket/socketServer").addInterceptors(new SpringWebSocketHandlerInterceptor()).setAllowedOrigins("*");
        //前台 不可以使用websocket环境，则使用sockjs进行模拟连接
        registry.addHandler(myHandler(), "sockjs/socketServer").addInterceptors(new SpringWebSocketHandlerInterceptor()).setAllowedOrigins("*").withSockJS();
    }

    public WebSocketHandler myHandler() {
        return new SpringWebSocketHandler();
    }

}

import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import com.google.common.reflect.TypeToken;
import com.google.gson.Gson;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.socket.*;
import org.springframework.web.socket.handler.TextWebSocketHandler;

/**
 * 相当于controller的处理器
 */
@Slf4j
public class SpringWebSocketHandler extends TextWebSocketHandler {
    // 保存所有的用户session
    private static final Map users = new HashMap<>();//这个会出现性能问题，最好用Map来存储，key用userid

    /**
     * 连接成功时候，会触发页面上onopen方法
     */
    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {


        users.put(session.getAttributes().get("userNo").toString(), session);
        System.out.println("connect to the websocket success......当前数量:" + users.size());
        //这块会实现自己业务，比如，当用户登录后，会把离线消息推送给用户
        //TextMessage returnMessage = new TextMessage("你将收到的离线");
        //session.sendMessage(returnMessage);
    }

    /**
     * 关闭连接时触发
     */
    @Override
    public void afterConnectionClosed(WebSocketSession session,
                                      CloseStatus closeStatus) throws Exception {

        log.info("connect websocket closed.......");
        users.remove(session.getAttributes().get("userNo"));

    }

    // 处理信息

    /**
     * js调用websocket.send时候，会调用该方法
     */
    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage message) throws Exception {//	        super.handleTextMessage(session, message);


        Gson gson = new Gson();
        // 将消息JSON格式通过Gson转换成Map
        // message.getPayload().toString() 获取消息具体内容
        Map msg = gson.fromJson(message.getPayload().toString(),
                new TypeToken>() {
                }.getType());
        log.info("handleMessage......." + message.getPayload() + "..........." + msg);
//	      session.sendMessage(message);
        // 处理消息 msgContent消息内容
        TextMessage textMessage = new TextMessage(msg.toString(), true);
        // 调用方法（发送消息给所有人）
        sendMessageToUsers(textMessage);
    }

    // 处理传输时异常
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        if (session.isOpen()) {
            session.close();
        }
        log.debug("websocket connection closed......");
        users.remove(session);
    }

    @Override
    public boolean supportsPartialMessages() {
        // TODO Auto-generated method stub
        return false;
    }


    /**
     * 给某个用户发送消息
     *
     * @param userName
     * @param message
     */
    public void sendMessageToUser(String userName, TextMessage message) {
        Iterator iterator = users.keySet().iterator();
        while (iterator.hasNext()) {
            String key = iterator.next();
            WebSocketSession webSocketSession = users.get(key);
            if (webSocketSession.getAttributes().get("userNo").equals(userName)) {
                try {
                    if (webSocketSession.isOpen()) {
                        webSocketSession.sendMessage(message);
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
                break;
            }

        }

    }

    /**
     * 给所有在线用户发送消息
     *
     * @param message
     */
    public void sendMessageToUsers(TextMessage message) {
        Iterator iterator = users.keySet().iterator();
        while (iterator.hasNext()) {
            String key = iterator.next();
            WebSocketSession webSocketSession = users.get(key);
            try {
                if (webSocketSession.isOpen()) {
                    webSocketSession.sendMessage(message);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.util.Map;

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;

/**
 * 创建握手（handshake）接口/拦截器
 *
 * @author lhb
 */
public class SpringWebSocketHandlerInterceptor extends HttpSessionHandshakeInterceptor {
    // 握手前

    /**
     * handler处理前调用,attributes属性最终在WebSocketSession里,可能通过webSocketSession.getAttributes().get(key值)获得
     */
    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler
            wsHandler, Map attributes) {
        if (request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest serverHttpRequest = (ServletServerHttpRequest) request;
            // 获取请求路径携带的参数
            String user = serverHttpRequest.getServletRequest().getParameter("user");
            attributes.put("userNo", user);
            return true;
        } else {
            return false;
        }
    }


    // 握手后
    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
                               Exception ex) {
        // TODO Auto-generated method stub
        super.afterHandshake(request, response, wsHandler, ex);
    }
}