我學習爪哇多線程。有導致死鎖的情況，并建議我如何修復，我需要一般建議。我明白什么意味著什么死鎖概念，但它可以解決一個問題。這是代碼：應用類：// in multithreading. class Util {     // Util class to sleep a thread     static void sleep(long millis)     {         try        {             Thread.sleep(millis);         }         catch (InterruptedException e)         {             e.printStackTrace();         }     } } 共享類：// This class is shared by both threads class Shared {     // first synchronized method     synchronized void test1(Shared s2)     {         System.out.println("test1-begin");         Util.sleep(1000);         // taking object lock of s2 enters         // into test2 method         s2.test2(this);         System.out.println("test1-end");     }     // second synchronized method     synchronized void test2(Shared s1)     {         System.out.println("test2-begin");         Util.sleep(1000);         // taking object lock of s1 enters         // into test1 method         s1.test1(this);         System.out.println("test2-end");     } } java 線程 1 類：class Thread1 extends Thread {     private Shared s1;     private Shared s2;     // constructor to initialize fields     public Thread1(Shared s1, Shared s2)     {         this.s1 = s1;         this.s2 = s2;     }     // run method to start a thread     @Override    public void run()     {         // taking object lock of s1 enters         // into test1 method         s1.test1(s2);     } } java 線程 2 類：class Thread2 extends Thread {     private Shared s1;     private Shared s2;     // constructor to initialize fields     public Thread2(Shared s1, Shared s2)     {         this.s1 = s1;         this.s2 = s2;     }     // run method to start a thread     @Override    public void run()     {         // taking object lock of s2         // enters into test2 method         s2.test2(s1);     } }