Java-Thread

package com.thread;

import java.util.Timer;
import java.util.TimerTask;

public class Threads extends Thread {
	public static void main(String[] args) {
		// 重写Thread类的run方法
		Thread thread = new Thread() {
			public void run() {
				System.out.println("createThread……");
			}
		};
		thread.start();
		// 实现runnable接口来启动一个线程，这种比较常用
		Thread thread2 = new Thread(new Runnable() {
			public void run() {
				System.out.println("ImplementsRunnable……");
			}
		});
		thread2.start();
		new Timer().schedule(new TimerTask() {

			@Override
			public void run() {
				// TODO Auto-generated method stub
				System.out.println("create Thread TimerTask()……");
			}

		}, 2000);

	}
}

设计两个线程，其中一个线程每次对j增加1，另外一个线程对j每次减少1。写出程序　　有错欢迎指出。

package com.thread;

public class ImplementsRunnable {
	private static int j;
    public static void main(String[] args) {
    	jia();
	}
     
    public static synchronized void inc() {
		  j--;
		  System.out.println(Thread.currentThread().getName()+"-inc"+j);
	}
    public static synchronized void dec() {
		  j++;
		  System.out.println(Thread.currentThread().getName()+"-dec"+j);
	}
    public static void jia() {
    	 new Thread(new Runnable(){
			@Override
			public void run() {
				// TODO Auto-generated method stub
				for (int i = 0; i < 100; i++) {
					inc();
				}
			}
    	}).start();
    	 new Thread(new Runnable(){
			@Override
			public void run() {
				// TODO Auto-generated method stub
				for (int i = 0; i < 100; i++) {
					dec();
				}
			}
    	}).start();
    }     
}