import java.io.*; 
//多線程編程 
public class MultiThread   
{ 
public static void main(String args[]) 
{ 
System.out.println("我是主線程!"); 
//下面創(chuàng)建線程實(shí)例thread1 
ThreadUseExtends thread1=new ThreadUseExtends(); 
//創(chuàng)建thread2時(shí)以實(shí)現(xiàn)了Runnable接口的THhreadUseRunnable類實(shí)例為參數(shù) 
Thread thread2=new Thread(new ThreadUseRunnable(),"SecondThread"); 
thread1.start();//啟動(dòng)線程thread1使之處于就緒狀態(tài) 
//thread1.setPriority(6);//設(shè)置thread1的優(yōu)先級為6 
//優(yōu)先級將決定cpu空出時(shí)，處于就緒狀態(tài)的線程誰先占領(lǐng)cpu開始運(yùn)行 
//優(yōu)先級范圍1到10,MIN_PRIORITY,MAX_PRIORITY,NORM_PAIORITY 
//新線程繼承創(chuàng)建她的父線程優(yōu)先級,父線程通常有普通優(yōu)先級即5NORM_PRIORITY 
System.out.println("主線程將掛起7秒!"); 
try 
{ 
Thread.sleep(7000);//主線程掛起7秒 
} 
catch (InterruptedException e) 
{ 
return; 
} 
System.out.println("又回到了主線程!"); 
if(thread1.isAlive()) 
{   
thread1.stop();//如果thread1還存在則殺掉他 
System.out.println("thread1休眠過長,主線程殺掉了thread1!"); 
} 
else 
System.out.println("主線程沒發(fā)現(xiàn)thread1,thread1已醒順序執(zhí)行結(jié)束了!"); 
thread2.start();//啟動(dòng)thread2 
System.out.println("主線程又將掛起7秒!"); 
try 
{ 
Thread.sleep(7000);//主線程掛起7秒 
} 
catch (InterruptedException e) 
{ 
return; 
} 
System.out.println("又回到了主線程!"); 
if(thread2.isAlive()) 
{   
thread2.stop();//如果thread2還存在則殺掉他 
System.out.println("thread2休眠過長，主線程殺掉了thread2!"); 
} 
else 
System.out.println("主線程沒發(fā)現(xiàn)thread2,thread2已醒順序執(zhí)行結(jié)束了!"); 
System.out.println("程序結(jié)束按任意鍵繼續(xù)!"); 
try 
{ 
System.in.read(); 
} 
catch (IOException e) 
{ 
System.out.println(e.toString()); 
} 

}//main 
}//MultiThread 


class ThreadUseExtends extends Thread 
//通過繼承Thread類,并實(shí)現(xiàn)它的抽象方法run() 
//適當(dāng)時(shí)候創(chuàng)建這一Thread子類的實(shí)例來實(shí)現(xiàn)多線程機(jī)制 
//一個(gè)線程啟動(dòng)后（也即進(jìn)入就緒狀態(tài)）一旦獲得CPU將自動(dòng)調(diào)用它的run()方法 
{ 

ThreadUseExtends(){}//構(gòu)造函數(shù) 
public void run() 
{ 
System.out.println("我是Thread子類的線程實(shí)例!"); 
System.out.println("我將掛起10秒!"); 
System.out.println("回到主線程,請稍等,剛才主線程掛起可能還沒醒過來！"); 
try 
{ 
sleep(10000);//掛起5秒 
} 
catch (InterruptedException e) 
{ 
return; 
} 
//如果該run()方法順序執(zhí)行完了,線程將自動(dòng)結(jié)束,而不會(huì)被主線程殺掉 
//但如果休眠時(shí)間過長,則線程還存活,可能被stop()殺掉 
} 
} 


class ThreadUseRunnable implements Runnable 
//通過實(shí)現(xiàn)Runnable接口中的run()方法,再以這個(gè)實(shí)現(xiàn)了run()方法的類 
//為參數(shù)創(chuàng)建Thread的線程實(shí)例 
{ 
//Thread thread2=new Thread(this); 
//以這個(gè)實(shí)現(xiàn)了Runnable接口中run()方法的類為參數(shù)創(chuàng)建Thread類的線程實(shí)例 
ThreadUseRunnable(){}//構(gòu)造函數(shù) 
public void run() 
{ 
System.out.println("我是Thread類的線程實(shí)例并以實(shí)現(xiàn)了Runnable接口的類為參數(shù)!"); 
System.out.println("我將掛起1秒!"); 
System.out.println("回到主線程,請稍等,剛才主線程掛起可能還沒醒過來！"); 
try 
{ 
Thread.sleep(1000);//掛起5秒 
} 
catch (InterruptedException e) 
{ 
return; 
} 
//如果該run()方法順序執(zhí)行完了,線程將自動(dòng)結(jié)束,而不會(huì)被主線程殺掉 
//但如果休眠時(shí)間過長,則線程還存活,可能被stop()殺掉 
} 

} 
//該程序可做的修改如改休眠時(shí)間或優(yōu)先級setPriority()