public class Service {
  Object object1 = new Object();

  public void methodA() {
    synchronized (object1) {
      System.out.println("methodA begin");
      boolean isContinueRun = true;
      //在这里执行一个死循环
      while (isContinueRun) {
        
      }
      System.out.println("methodA end");
    }
  }

  Object object2 = new Object();

  public void methodB() {
    synchronized (object2) {
      System.out.println("methodB begin");
      System.out.println("methodB end");
    }
  }
}

import service.Service;

public class ThreadA extends Thread {

  private Service service;

  public ThreadA(Service service) {
    super();
    this.service = service;
  }

  @Override
  public void run() {
    service.methodA();
  }

}

import service.Service;

public class ThreadB extends Thread {

  private Service service;

  public ThreadB(Service service) {
    super();
    this.service = service;
  }

  @Override
  public void run() {
    service.methodB();
  }

}

import service.Service;
import extthread.ThreadA;
import extthread.ThreadB;

public class Run {

  public static void main(String[] args) {
    Service service = new Service();

    ThreadA athread = new ThreadA(service);
    athread.start();

    ThreadB bthread = new ThreadB(service);
    bthread.start();
  }

}

public class Service {
//  Object object1 = new Object();

  public void methodA() {
    synchronized (this) {
      System.out.println("methodA begin");
      boolean isContinueRun = true;
      //在这里执行一个死循环
      while (isContinueRun) {
        
      }
      System.out.println("methodA end");
    }
  }

//  Object object2 = new Object();

  public void methodB() {
    synchronized (this) {
      System.out.println("methodB begin");
      System.out.println("methodB end");
    }
  }
}