package thread;/** * Learn Java from https://www.liaoxuefeng.com/ *  * @author liaoxuefeng */public class Main {   static final Object LOCK_A = new Object();   static final Object LOCK_B = new Object();   public static void main(String[] args) {      new Thread1().start();      new Thread2().start();   }   static void sleep1s() {      try {         Thread.sleep(1000);      } catch (InterruptedException e) {         e.printStackTrace();      }   }}class Thread1 extends Thread {   public void run() {      System.out.println("Thread-1: try get lock A...");      synchronized (Main.LOCK_A) {         System.out.println("Thread-1: lock A got.");         Main.sleep1s();         System.out.println("Thread-1: try get lock B...");         synchronized (Main.LOCK_B) {            System.out.println("Thread-1: lock B got.");            Main.sleep1s();         }         System.out.println("Thread-1: lock B released.");      }      System.out.println("Thread-1: lock A released.");   }}class Thread2 extends Thread {   public void run() {      System.out.println("Thread-2: try get lock A...");      synchronized (Main.LOCK_A) {         System.out.println("Thread-2: lock A got.");         Main.sleep1s();         System.out.println("Thread-2: try get lock B...");         synchronized (Main.LOCK_B) {            System.out.println("Thread-2: lock B got.");            Main.sleep1s();         }         System.out.println("Thread-2: lock B released.");      }      System.out.println("Thread-2: lock A released.");   }}