1.基本的线程机制

　　定义任务

public class LiftOff implements Runnable{    protected int countDown = 10;    private static int taskCount = 0;    private final int id = taskCount++;    public LiftOff(){}    public LiftOff(int countDown){        this.countDown = countDown;    }    public String status() {        return "#"+id+"("+(countDown>0?countDown:"Liftoff!")+"). ";    }    @Override    public void run() {        while(countDown-->0){            System.out.println(status());            Thread.yield();        }    }}

　　使用Thread类驱动任务

public class BasicThreads {    public static void main(String[] args) {        Thread t = new Thread(new LiftOff());        t.start();        System.out.println("Waiting for LiftOff");    }}

　　任务执行完之前垃圾回收器不会回收线程对象。