7.2.2 多線程例子
下面這個例子創(chuàng)建了三個單獨的線程，它們分別打印自己的“Hello World":
//Define our simple threads.They will pause for a short time
//and then print out their names and delay times
public class TestThread extends Thread {
private String whoami; //定義其屬性
private int delay;
//Our constructor to store the name (whoami)
//and time to sleep (delay)
public TestThread(String s, int d) { //定義了一個線程的構(gòu)造函數(shù)
whoami = s;
delay = d;
}
//Run - the thread method similar to main()
//When run is finished, the thread dies.
//Run is called from the start() method of Thread
public void run() { //運行線程
//Try to sleep for the specified time
try {
sleep(delay); //讓線程進行睡眠
}
catch(InterruptedException e) {
}
//Now print out our name
System.out.println("Hello World!"+whoami+""+delay);
}
}
/** * Multimtest. A simple multithread thest program */
public static void main(String[] args) {
TestThread t1,t2,t3;
//Create our test threads
t1 = new TestThread("Thread1",(int)(Math.readom()*2000)); //實例化線程
t2 = new TestThread("Thread2",(int)(Math.readom()*2000));
t3 = new TestThread("Thread3",(int)(Math.readom()*2000));
//Start each of the threads
t1.start(); //啟動線程
t2.start();
t3.start();
}
}
7.2.3 啟動一個線程
程序啟動時總是調(diào)用main()函數(shù)，因此main()是我們創(chuàng)建和啟動線程的地方：
t1 = new TestThread("Thread1", (int)(Math.readom()*2000));
這一行創(chuàng)建了一個新的線程。后面的兩個參數(shù)傳遞了線程的名稱和線程在打印信息前的延 時時間。因為我們直接控制線程，我們必須直接啟動它：
t1.start();