java世界

//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，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
//一個線程啟動后（也即進(jìn)入就緒狀態(tài)）一旦獲得CPU將自動調(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,線程將自動結(jié)束,而不會被主線程殺掉
//但如果休眠時間過長,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 jn0-120  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,線程將自動結(jié)束,而不會被主線程殺掉
//但如果休眠時間過長,則線程還存活,可能被stop()殺掉
}