sleep()與wait()的差別（java筆記-多線程）

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 1 package test; 2  3 public class test1 { 4  5     public static void main(String[] args) { 6  7         new Thread(new thread1()).start(); 8         try { 9             Thread.sleep(5000);10         } catch (InterruptedException e) {11 12             e.printStackTrace();13         }14         new Thread(new thread2()).start();15 16     }17 }18 19 class thread1 implements Runnable {20 21     @Override22     public void run() {23 24         synchronized (test1.class) {25             System.out.println("here is thread1");26             System.out.println("thread1 is waiting");27 28             try {29                 test1.class.wait();// 調用wait，會釋放線程鎖，進入等待鎖定池，直到調用notify方法喚醒，再次進入對象鎖定池準備擷取對象鎖進入運行狀態。30 31             } catch (InterruptedException e) {32 33                 e.printStackTrace();34             }35             System.out.println("thread1 is going");36             System.out.println("thread1 is over");37         }38     }39 }40 41 class thread2 implements Runnable {42 43     @Override44     public void run() {45         //46         synchronized (test1.class) {47             System.out.println("here is thread2");48             System.out.println("thread2 is sleeping");49             test1.class.notify();50             try {51                 Thread.sleep(4000);// 調用sleep，會等待相應時間，等待時線程鎖不釋放，時間到了會進入運行狀態；52                 System.out.println("thread2 is going");53                 System.out.println("thread2 is over");54             } catch (InterruptedException e) {55                 e.printStackTrace();56             }57         }58     }59 }

運行結果：

here is thread1thread1 is waitinghere is thread2thread2 is sleepingthread2 is goingthread2 is overthread1 is goingthread1 is over

注釋掉49行的“test1.class.notify();”

程式會一直處於掛起狀態：

 

here is thread1thread1 is waitinghere is thread2thread2 is sleepingthread2 is goingthread2 is over

 

sleep()方法屬於Thread類；wait()方法屬於Object類。

在調用sleep()方法的過程中，線程不會釋放對象鎖。而當調用wait()方法的時候，線程會放棄對象鎖，進入等待此對象的等待鎖定池，只有針對此對象調用notify()方法後本線程才進入對象鎖定池準備。

感謝大神 Hongten；

 

sleep()與wait()的差別（java筆記-多線程）