运行 具有特定条件和时间的线程

Run Thread with specific condition and time

我想创建一个条件,当用户下订单时,有一个线程 运行s 持续 20 秒以检查数据库付款状态是完成还是待处理,如果完成则线程将停止,如果它仍然挂起那么线程将继续 运行 20 秒并更新数据库中的状态被取消,我正在使用 mybatis 和 XML mapper

here is my code

public class PaymentCheck implements Runnable{
   private String username;
    public PaymentCheck(String username) {
        this.username = username;
    }

    @Override
    public void run() {
        SqlSession session = MyBatisUtil.getSqlSessionFactory().openSession();
        Booking bookStatus =  session.selectOne("User.check",username);

        String status = bookStatus.getPayment_status();
        while (status.equalsIgnoreCase("pending")){
            final Timer timer = new Timer();
            timer.scheduleAtFixedRate(new TimerTask() {
                int i = 6; // Time in seconds

                public void run() {
                    System.out.println(i--);
                    if (i < 0) {
                        timer.cancel();

                    }
                }
            }, 0, 1000);
        }
    }
}

here is my code in controller

@RequestMapping(value = "/Booking", method = RequestMethod.POST,consumes = "application/json", produces = "application/json")
public ResponseEntity<?> Booking(@RequestBody JSONObject jobj, @RequestHeader(HEADER)  String header) throws RestClientException, JsonProcessingException {

    String username = userRepo.claimToken(SECRET,PREFIX,header);
    jobj.put("username",username);
    HttpHeaders headers = new HttpHeaders();
    MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
    headers.setContentType(type);
    System.out.println(jobj.toString());
    HttpEntity<JSONObject> formEntity = new HttpEntity<JSONObject>(jobj, headers);
    JSONObject json = restTemplate.postForEntity("http://localhost:8080/hotel/Booking", formEntity, JSONObject.class).getBody();
    String message = String.valueOf(json.get("Booking Status"));

    if (!message.equalsIgnoreCase("Failed")) {
        System.out.println("json:" + json.toString());
        System.out.println(username);
        PaymentCheck tq = new PaymentCheck(username);
        tq.run();
        return new ResponseEntity<>(json,HttpStatus.CREATED);
    }else{

        return new ResponseEntity<>(json,HttpStatus.CREATED);
    }


}

这是数据库

它没有显示任何错误,但也没有改变任何东西...

你似乎把这个复杂化了。

问题 1:您的线程每秒轮询一次,但控制器响应不会等待更新发生才响应客户。所以投票没有意义。

问题 2:您的线程实际上并未更新数据库。

解决方案

  1. 在主线程中执行检查,轮询然后响应。
  2. 设置一个定时任务,在未来20秒后执行一次单次执行更新

使用通用 JDBC.

的解决方案 2 的示例代码
private Timer timer = new Timer();

@RequestMapping(value = "/Booking", method = RequestMethod.POST,consumes = "application/json", produces = "application/json")
public ResponseEntity<?> Booking(@RequestBody JSONObject jobj, @RequestHeader(HEADER)  String header) throws RestClientException, JsonProcessingException {

    String username = userRepo.claimToken(SECRET,PREFIX,header);
    jobj.put("username",username);
    HttpHeaders headers = new HttpHeaders();
    MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
    headers.setContentType(type);
    System.out.println(jobj.toString());
    HttpEntity<JSONObject> formEntity = new HttpEntity<JSONObject>(jobj, headers);
    JSONObject json = restTemplate.postForEntity("http://localhost:8080/hotel/Booking", formEntity, JSONObject.class).getBody();
    String message = String.valueOf(json.get("Booking Status"));

    if (!message.equalsIgnoreCase("Failed")) {
        System.out.println("json:" + json.toString());
        System.out.println(username);
        TimerTask tt = new PaymentCheck(username);
        timer.schedule(tt, 20000);
        return new ResponseEntity<>(json,HttpStatus.CREATED);
    }else{
        return new ResponseEntity<>(json,HttpStatus.CREATED);
    }
}

public class PaymentCheck extends TimerTask {

   private static final MYQUERY = "update User.check set payment_status = 'cancelled' where payment_status = 'pending' and user = ?";

   private String username;

   public PaymentCheck(String username) {
       this.username = username;
   }

    @Override
    public void run() {
        try (Connection cn = ...) {
            try (Statement stmt = new PreparedStatement(MYQUERY))
            {
                stmt.setString(1, username);
                stmt.execute();
                cn.commit();
            }
        }
    }
}