java定时任务代码实现

在JDK库中,有两种技术可以实现定时任务的类。一种是使用Timer，另外一个则是ScheduledThreadPoolExecutor。

1.Timer

public class Mytask extends TimerTask {
    @Override
    public void run() {
        writeStringToFile("C:\\Users\\hp\\Desktop\\aa.txt");
    }

    public void writeStringToFile(String filePath) {
        try {
            File file = new File(filePath);
            PrintStream ps = new PrintStream(new FileOutputStream(file));
            Date date = new Date();
            long time = date.getTime();
            ps.print(time);
            ps.append("++++++++++++++++++++");// 在已有的基础上添加字符串
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}
class TimerDemo {
    public static void main(String[] args) {
        Timer timer = new Timer();
         timer.schedule(new Mytask(), new Date());
    }
}

2.ScheduledThreadPoolExecutor

class ScheduledThreadPoolExecutorDemo{

    public static void writeStringToFile(String filePath) {
        //文件的续写
        FileWriter fw = null;
        try {
            fw = new FileWriter(filePath,true);
            //写入换行
            fw.write("\r\n");//Windows平台下用\r\n，Linux/Unix平台下用\n
            Date date = new Date();
            long time = date.getTime();
            fw.write(time+"++++++++++++++++++++");
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(5);
        scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                writeStringToFile("C:\\Users\\hp\\Desktop\\aa.txt");
                System.out.println(new Date());
            }
        },10000,10000, TimeUnit.MILLISECONDS);
    }
}

本文仅两种基本的使用方法，关于更多的使用方法、以及两者的区别还请读者自己翻看源码！