应用一直尝试重启消息服务，如何只运行消息服务一次？

Question

我有一个运行带有 2 个可运行程序的执行程序服务的应用程序，这些可运行程序启动进程以从 rfid reader 接收消息。此 reader 从 messagelistener 收到一条消息，其中包含标签经过 reader 后的标签信息。我收到了标签信息，但在它运行时收到错误，因为它一直在尝试重新启动 messagelistenerservice。试图只添加需要查看的代码。我如何只启动一次 messagelistener 服务，这样我就不会收到此错误。谢谢！

这是错误：

java.io.IOException: Could not listen on port 3500. Is that port in use?
at com.alien.enterpriseRFID.notify.MessageListenerService.startService(MessageListenerService.java:232)
at com.rfidreader.volvo.model.AlienReader.startMessageService(AlienReader.java:99)
at com.rfidreader.volvo.model.AlienReader.<init>(AlienReader.java:73)
at com.rfidreader.volvo.VolvoRfidReaderApplication.lambda(VolvoRfidReaderApplication.java:54)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

这是 reader:

的 @Component

@Component
@Scope("prototype")
public class AlienReader extends AlienClass1Reader implements 
TagTableListener, MessageListener{

 private String ipaddress;
 private int port;
 private String username;
 private String password;
 private TagTable tagTable = new TagTable();
 private MessageListenerService service;
 private TagTableListener tagTableListener;


 private static final Logger log =LogManager.getLogger(AlienReader.class);

public AlienReader(String ipaddress, int port, String username, String pwd) 
throws UnknownHostException, AlienReaderException, InterruptedException{
    super(ipaddress, port);
    this.ipaddress=ipaddress;
    this.port=port;
    this.username=username;
    this.password=pwd;
    startMessageService();


    }

public void startMessageService() throws UnknownHostException, 
 AlienReaderException, InterruptedException{


    if(ipaddress.equals("222.22.222.22")){
        service=new MessageListenerService(3400);
        service.setMessageListener(this);
    }else if (ipaddress.equals("333.33.333.33")){
        service=new MessageListenerService(3500);
        service.setMessageListener(this);
    }

    try{
        service.startService();
     }catch(IOException e){
         e.printStackTrace();
     }
    log.info("Service has started on : "+ipaddress);
    setReaderConfig();
}

public void setReaderConfig() throws UnknownHostException, AlienReaderException, InterruptedException{
    log.info("Setting up reader");
     this.setUsername(username);
    this.setPassword(password);
      String myIP=InetAddress.getLocalHost().getHostAddress();
    try{
        this.open();
        this.setNotifyAddress(myIP,service.getListenerPort());
        this.setNotifyFormat(AlienClass1Reader.TEXT_FORMAT);
        this.setNotifyTrigger("TrueFalse");
        this.setNotifyMode(AlienClass1Reader.ON);
        this.autoModeReset();
        this.setAutoMode(AlienClass1Reader.ON);
        tagTable.setPersistTime(2000);
        this.close();
        }catch(AlienReaderException e){
            log.error("Reader "+ this.getIPAddress()+" did not connect."+e.getMessage());

        }


}


@Override
public synchronized void messageReceived(Message msg) {
     if(msg instanceof ErrorMessage){
         log.error("Notify error from "+ msg.getReaderIPAddress());

     }else if (msg.getTagCount() == 0){

                log.info("No tags!");
     }else{
        log.info("Message received from: "+msg.getReaderIPAddress());
         String location = msg.getReaderIPAddress();
        Tag[] tagL=msg.getTagList();
        for (int i=0;i<msg.getTagCount(); i++){
            Tag tag = msg.getTag(i);
            this.tagTable.addTag(tag);

            log.info("Tag ID: "+tag.getTagID()+ " Last Seen: "+tag.getRenewTime()+ " Receive Antenna: "+tag.getReceiveAntenna()+ " ip: "+ location);

        }

      }
}

下面是启动 String boot app 的主要方法：

public static void main(String[] args) throws UnknownHostException, AlienReaderException, InterruptedException {
    //SpringApplication.run(VolvoRfidReaderApplication.class, args);
    ConfigurableApplicationContext run = SpringApplication.run(VolvoRfidReaderApplication.class, args);
    VolvoRfidReaderApplication app = run.getBean(VolvoRfidReaderApplication.class);
    app.run();
}

private void run(){
    Runnable r1= () -> {
        for(int i=0;i<30;++i){
            //System.out.println("task 1");
            try {
                new AlienReader("222.22.222.22", 22, "username","password");
            } catch (UnknownHostException | AlienReaderException | InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try{
                Thread.sleep(1000);
            }catch(Exception ignored){
        }
    }
};

    Runnable r2= () -> {
        for(int i=0;i<30;++i){
            //System.out.println("task 2");
            try {
                new AlienReader("333.33.333.33", 22, "username","password");
            } catch (UnknownHostException | AlienReaderException | InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try{
                Thread.sleep(1000);
            }catch(Exception ignored){
        }
    }
    };

        ExecutorService service = Executors.newFixedThreadPool(2);
        service.submit(r1);
        service.submit(r2);


        service.shutdown();
}

Answer 1

这里的主要错误是：

Could not listen on port 3500. Is that port in use?

端口一次只能由一台计算机上的一件事使用。因此，例如，如果我有一个 spring-boot web-app，并且它运行在端口 8080 上，我不能在不告知第二个使用不同的端口，如 8081。

你在这里有一些选择 2 个不同端口的逻辑：

if(ipaddress.equals("222.2223")){
    service=new MessageListenerService(3400);
    service.setMessageListener(this);
}else if (ipaddress.equals("222.2224")){
    service=new MessageListenerService(3500);
    service.setMessageListener(this);
}

不幸的是，在您的 for 循环中，您似乎使用相同的 IP 启动了多个 reader（奇怪的是，在这种情况下，这似乎与结尾的 23 或 24 不匹配，但我'我可能只是遗漏了什么）。

for(int i=0;i<30;++i){
    //System.out.println("task 1");
    try {
        new AlienReader("222.222", 22, "username","password");
    } catch (UnknownHostException | AlienReaderException | InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try{
        Thread.sleep(1000);
    }catch(Exception ignored){
}

您需要确保每次启动服务时，它都有一个完全唯一的端口，未被计算机上的任何其他东西使用，否则您会一直看到此错误。

我认为你应该简化问题。现在每个运行nable 中只有运行个 reader，确保它们有自己不同的端口（我建议你从一开始就手动传入），并将其扩展到更多一旦成功。

应用一直尝试重启消息服务，如何只运行消息服务一次？

App keeps trying to restart message service, how do I run the message service only once?

spring-boot

executorservice