1.新建一個(gè)springboot工程,添加一個(gè)maven依賴

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>

文件目錄結(jié)構(gòu)如下:

image.png

2. 創(chuàng)建websocket服務(wù)端類

MoneyServer.java

/**
 * @author Page
 * @date 2019-07-02 10:00
 * @description websocket 服務(wù)
 */

@Component
@Slf4j
@ServerEndpoint(value = "/money/{userId}", decoders = {
        MessageDecoder.class,}, encoders = {MessageEncoder.class,}, configurator = MoneyRepayConfig.class)
public class MoneyServer {
    private static final Map<String, Session> SESSION_MAP = new HashMap<>();

    @OnOpen
    public void connect(Session session, @PathParam("userId") String userId) {
        // 將session按照房間名來存儲(chǔ)，將各個(gè)房間的用戶隔離
        SESSION_MAP.put(userId, session);
        log.info("websocket成功連接!");
    }

    @OnMessage
    public void repay(RepayReq req, Session session) {
        SESSION_MAP.put(req.getUserId(), session);
        log.info("{}正在還錢:{} 元", req.getName(), req.getMoneyNum());
    }

    public void send(RepayResultRes res) throws IOException, EncodeException {
        if (SESSION_MAP.get(res.getUserId()) == null) {
            log.info("沒有找到連接，消息無法推送");
            return;
        }
        SESSION_MAP.get(res.getUserId()).getBasicRemote().sendObject(res);
        log.info("{}成功還錢:{} 元翰苫，userId:{},還錢結(jié)果:{}", res.getName(),
                res.getMoneyNum(), res.getUserId(), res.isRepayResult()?"還成功" :"失敗了");
    }
}

這里我還添加了一個(gè)自定義的解碼器和一個(gè)編碼器,用于解析java對(duì)象和前端傳來的字符串,以及一個(gè)自定義的websocket配置類.不過在這個(gè)配置類里邊目前什么都沒有做.
MessageDecoder.java

@Slf4j
public class MessageDecoder implements Decoder.Text<RepayReq> {
 
    @Override
    public RepayReq decode(String s) {
        log.info("primal string" + s);
        RepayReq repayReq = null;
        try {
            repayReq = JSONObject.parseObject(s, RepayReq.class);
        } catch (Exception ex) {
            log.error(ex.getMessage());
        }
        return repayReq;
    }
 
    @Override
    public boolean willDecode(String s) {
          
        return (s != null);
    }
 
    @Override
    public void init(EndpointConfig endpointConfig) {
        // do nothing.
    }
 
    @Override
    public void destroy() {
        // do nothing.
    }
}

MessageEncoder.java

@Slf4j
public class MessageEncoder implements Encoder.Text<RepayResultRes> {

    @Override
    public String encode(RepayResultRes object) {

        String s = null;
        try {

            s = JSONObject.toJSONString(object);
            log.info("primal: " + object.toString());

        } catch (Exception ex) {
            log.error(ex.getMessage());
        }
        return s;
    }

    @Override
    public void init(EndpointConfig endpointConfig) {
        // do nothing.
    }

    @Override
    public void destroy() {
        // do nothing.
    }
}

MoneyRepayConfig.java

/**
 * @author Page
 * @date 2019-07-05 17:00
 * @description
 */
@Slf4j
public class MoneyRepayConfig extends ServerEndpointConfig.Configurator{
    @Override
    public boolean checkOrigin(String originHeaderValue) {
        log.info("1=========originHeaderValue====={}", originHeaderValue);
        return true;
    }

    @Override
    public <T> T getEndpointInstance(Class<T> clazz) throws InstantiationException {
        log.info("2========{}========={}==",clazz, super.getEndpointInstance(clazz));
        return super.getEndpointInstance(clazz);
    }

    @Override
    public String getNegotiatedSubprotocol(List<String> supported, List<String> requested) {
        log.info("3========{}====={}======{}", supported, requested, super.getNegotiatedSubprotocol(supported, requested));
        return super.getNegotiatedSubprotocol(supported, requested);
    }

    @Override
    public List<Extension> getNegotiatedExtensions(List<Extension> installed, List<Extension> requested) {
        log.info("4======{}====={}======{}", installed, requested, super.getNegotiatedExtensions(installed, requested));
        return super.getNegotiatedExtensions(installed, requested);
    }

    @Override
    public void modifyHandshake(ServerEndpointConfig sec, HandshakeRequest request, HandshakeResponse response) {
        log.info("5======{}======{}======{}", sec, request, response);
        super.modifyHandshake(sec, request, response);
    }
}

ServerEndpointConfig 里有幾個(gè)可以重寫的方法,通過這些方法可以獲取websocket的信息以及對(duì)連接的一些信息進(jìn)行修改等.

3. 創(chuàng)建WebSocketConfig

通過這個(gè)配置類對(duì)websocket服務(wù)進(jìn)行發(fā)布

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

4.創(chuàng)建controller

這里我還創(chuàng)建了一個(gè)控制器類,用于模擬服務(wù)器的響應(yīng),發(fā)送消息通知客戶端.
RepaySuccessController.java

/**
 * @author Page
 * @Date: 2019-07-02 10:36
 * @Description:
 */

@Controller
@RequestMapping("/money")
public class RepaySuccessController {
    @Resource
    MoneyServer moneyServer;

    @PostMapping("/repaySuccess")
    public void repaySuccess(RepayResultRes req) throws IOException, EncodeException {
        moneyServer.send(req);
    }
}

工程代碼已經(jīng)放在我的github倉庫,有需要的可以下載

地址:歡迎參觀
更多關(guān)于websocket的內(nèi)容,可以參考官方文檔:
https://docs.oracle.com/javaee/7/api/javax/websocket/server/package-summary.html