package java.lang;
public class Thread implements Runnable {
     public Thread( );
     public Thread(Runnable target);
     public Thread(ThreadGroup group, Runnable target);
     public Thread(String name);
     public Thread(ThreadGroup group, String name);
     public Thread(Runnable target, String name);
     public Thread(ThreadGroup group, Runnable target, String name);
     public Thread(ThreadGroup group, Runnable target, String name,
                   long stackSize);
     public void start( );
     public void run( ); 
}

public class TestInterrupted {
     public static void main(String args[]) throws InterruptedException{
         Foo foo = new Foo();
         foo.start();
         Thread.currentThread().sleep(100);  //注释掉这句有什么影响呢？
         System.out.println("before interrupt");
         foo.interrupt();
         System.out.println("after interrupt");
     } }  

class Foo extends Thread {
     public void run() {
         try{
             while(!isInterrupted()) {
                 System.out.println("start calculating...");
                 double pi = 3.1415926;
                 for(int i=0; i<5; i++) {
                     for(long j=0; j<1000000; j++) {
                         pi *= pi;
                     }
                     System.out.println("i="+i);
                 }
                 System.out.println("before sleep");
                 sleep(5000);    //注释掉这句及相关的try...catch语句，又怎样呢？
                 System.out.println("after sleep");
             }
         } catch(InterruptedException ex) {
             ex.printStackTrace(System.out);
         }
     }
}

public class TestLock {
     public static void main(String args[])
           throws InterruptedException{
         Foo foo = new Foo();
         foo.start();
         Thread t = Thread.currentThread();
         for(int i=0; i<10; i++) {
             foo.setInt2("Main", i, i+20);
         }
     }
}

class Foo extends Thread{
     protected int arrI[] = new int[10];

     public void run() {
         try {
             for(int i=0; i<10; i++) {    
                 setInt("Foo", i, i);   
             }    
         } catch(InterruptedException ex) {}
     } 

     public synchronized void setInt(String from, int pos, int val)
               throws InterruptedException{
         arrI[pos] = val;
         sleep((long)(Math.random()*5000));
         System.out.println(from+":arrI["+pos+"]="+arrI[pos]);
     }

      public void setInt2(String from, int pos, int val)
               throws InterruptedException {
         synchronized(arrI){
             arrI[pos] = val;
             sleep((long)(Math.random()*5000));
             System.out.println(from+":arrI["+pos+"]="+arrI[pos]);
         }
     } 
}

Foo:arrI[0]=0 
Main:arrI[0]=0 
Main:arrI[1]=21 
Main:arrI[2]=22 
Foo:arrI[1]=21 
Main:arrI[3]=23 
Main:arrI[4]=24 
Main:arrI[5]=25 
Foo:arrI[2]=2 
Main:arrI[6]=26 
Main:arrI[7]=27 
Foo:arrI[3]=3 
Foo:arrI[4]=4 
Main:arrI[8]=28 
Main:arrI[9]=29 
Foo:arrI[5]=5 
Foo:arrI[6]=6 
Foo:arrI[7]=7 
Foo:arrI[8]=8 
Foo:arrI[9]=9

public class TestLock1 {
     public static void main(String args[])
           throws InterruptedException{
         Foo1 foo = new Foo1();
         foo.start();
         Thread t = Thread.currentThread();
         for(int i=0; i<10; i++) {
             foo.setInt2("Main", i, i+20);
         }
     } 
}  

class Foo1 extends Thread{
     protected int arrI[] = new int[10];

     public void run() {
         try{    
             for(int i=0; i<10; i++) {    
                 setInt("Foo", i, i);    
             }    
         }catch(InterruptedException ex){} 
     }

     public synchronized void setInt(String from, int pos, int val)
           throws InterruptedException{
         arrI[pos] = val;
         sleep((long)(Math.random()*5000));
         System.out.println(from+":arrI["+pos+"]="+arrI[pos]);
     }

     public synchronized void setInt2(String from, int pos, int val)
           throws InterruptedException{
         arrI[pos] = val;
         sleep((long)(Math.random()*5000));
         System.out.println(from+":arrI["+pos+"]="+arrI[pos]);
     }
}