[問題] 關於JAVA synchronized的問題?

[SST2000 (BMW 428i)]

  請問各位,下面這個範例程式為什麼輸出只會有線程0執行??
ackage Thread02;
public class main {
    public static void main(String[] args) {
        Mythread02 T2=new Mythread02();
        Thread t1=new Thread(T2);
        Thread t2=new Thread(T2);
        Thread t3=new Thread(T2);
        t1.start();
        t2.start();
        t3.start();
}

下面是宣告的class

package Thread02;
public class Mythread02 implements Runnable {
    private int number=100;
    public void run() {
        synchronized (this) {
            try {
                Thread.sleep(100);

//---------------------------------------------------------------//
                while (true) {
                    if (number > 0) {
                        System.out.println("This is Mythread02 " +
Thread.currentThread().getName() + "---" + number--);
                    } else {
                        break;
                    }
                }

//---------------------------------------------------------------//]
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
   }
}



----------------------------下面是輸出結果-------------------------
This is Mythread02 Thread-0---100
This is Mythread02 Thread-0---99
This is Mythread02 Thread-0---98
This is Mythread02 Thread-0---97
This is Mythread02 Thread-0---96
This is Mythread02 Thread-0---95
This is Mythread02 Thread-0---94
This is Mythread02 Thread-0---93
This is Mythread02 Thread-0---92
This is Mythread02 Thread-0---91
This is Mythread02 Thread-0---90
This is Mythread02 Thread-0---89
This is Mythread02 Thread-0---88
This is Mythread02 Thread-0---87
This is Mythread02 Thread-0---86
This is Mythread02 Thread-0---85
This is Mythread02 Thread-0---84
This is Mythread02 Thread-0---83
This is Mythread02 Thread-0---82
This is Mythread02 Thread-0---81
This is Mythread02 Thread-0---80
This is Mythread02 Thread-0---79
This is Mythread02 Thread-0---78
This is Mythread02 Thread-0---77
This is Mythread02 Thread-0---76
This is Mythread02 Thread-0---75
This is Mythread02 Thread-0---74
This is Mythread02 Thread-0---73
This is Mythread02 Thread-0---72
This is Mythread02 Thread-0---71
This is Mythread02 Thread-0---70
This is Mythread02 Thread-0---69
This is Mythread02 Thread-0---68
This is Mythread02 Thread-0---67
This is Mythread02 Thread-0---66
This is Mythread02 Thread-0---65
This is Mythread02 Thread-0---64
This is Mythread02 Thread-0---63
This is Mythread02 Thread-0---62
This is Mythread02 Thread-0---61
This is Mythread02 Thread-0---60
This is Mythread02 Thread-0---59
This is Mythread02 Thread-0---58
This is Mythread02 Thread-0---57
This is Mythread02 Thread-0---56
This is Mythread02 Thread-0---55
This is Mythread02 Thread-0---54
This is Mythread02 Thread-0---53
This is Mythread02 Thread-0---52
This is Mythread02 Thread-0---51
This is Mythread02 Thread-0---50
This is Mythread02 Thread-0---49
This is Mythread02 Thread-0---48
This is Mythread02 Thread-0---47
This is Mythread02 Thread-0---46
This is Mythread02 Thread-0---45
This is Mythread02 Thread-0---44
This is Mythread02 Thread-0---43
This is Mythread02 Thread-0---42
This is Mythread02 Thread-0---41
This is Mythread02 Thread-0---40
This is Mythread02 Thread-0---39
This is Mythread02 Thread-0---38
This is Mythread02 Thread-0---37
This is Mythread02 Thread-0---36
This is Mythread02 Thread-0---35
This is Mythread02 Thread-0---34
This is Mythread02 Thread-0---33
This is Mythread02 Thread-0---32
This is Mythread02 Thread-0---31
This is Mythread02 Thread-0---30
This is Mythread02 Thread-0---29
This is Mythread02 Thread-0---28
This is Mythread02 Thread-0---27
This is Mythread02 Thread-0---26
This is Mythread02 Thread-0---25
This is Mythread02 Thread-0---24
This is Mythread02 Thread-0---23
This is Mythread02 Thread-0---22
This is Mythread02 Thread-0---21
This is Mythread02 Thread-0---20
This is Mythread02 Thread-0---19
This is Mythread02 Thread-0---18
This is Mythread02 Thread-0---17
This is Mythread02 Thread-0---16
This is Mythread02 Thread-0---15
This is Mythread02 Thread-0---14
This is Mythread02 Thread-0---13
This is Mythread02 Thread-0---12
This is Mythread02 Thread-0---11
This is Mythread02 Thread-0---10
This is Mythread02 Thread-0---9
This is Mythread02 Thread-0---8
This is Mythread02 Thread-0---7
This is Mythread02 Thread-0---6
This is Mythread02 Thread-0---5
This is Mythread02 Thread-0---4
This is Mythread02 Thread-0---3
This is Mythread02 Thread-0---2
This is Mythread02 Thread-0---1


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→ charlie0275: 在 main 主執行緒加上sleep多等幾秒看看
→ LZN: 因為synchronized (this)的關係
→ ssccg: 在synchronized裡面放sleep並不會把lock釋放
→ ssccg: 另外以你的寫法是搶到的Thread就會一次跑完，如果你是要模
→ ssccg: 擬每個數字都重搶一次，Thread中斷應該放在迴圈裡吧
→ ssccg: while (true) {
→ ssccg:     synchronized (this) {
→ ssccg:         if (...) {...} else { break; }
→ ssccg:     }
→ ssccg:     Thread.sleep(100);
→ ssccg: }
→ ssccg: 我猜你想做的效果是這樣
→ ssccg: 如果一定要synchonized在外面，要用wait/notify來控制lock