How to access a method in order?

Question

Java

public class SeleniumBufferead implements Runnable {
    private void send() throws Exception{
//Тут ещё другой код коонечно
       sendMessages.send("каккие-то числа", "Сообщение");
 Thread.sleep(1000000);
    }

    @Override
    public void run() {
        try {
            this.send();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

And there is an appeal to this class. Like new Thread(new SeleniumBufferead ()).start()
How to do it, if several threads call this method at the same time, then a queue appears. While one thread does not finish, the other will not start working with it
Through synchronized??

Answer 1

synchronized method is synchronized on this. Won't fit. For example, you can pass everywhere the object on which you want to synchronize.

public class SeleniumBufferead implements Runnable {
    private final Object lock;
    public SeleniumBufferead(Object lock) {
        this.lock = lock;
    }
    private void send() {
        synchronized(lock) {
             //code
        }
    }
}
.....
final Object lock = new Object();
new Thread(new SeleniumBufferead(lock)).start();
new Thread(new SeleniumBufferead(lock)).start();

In general, I advise you to read concurrency in practice .