在java中创建后台线程的最佳方法

private static void checkDatabaseEveryXMinutes() {
    new Thread() {
        public void run() {
            while (true) {
                try {
                    Thread.sleep(checkingAfterEveryXMinutes);
                    getDataFromDatabase();
                } catch (InterruptedException ex) {
                    //log here
                } catch (Exception e) {
                    //log here
                }
            }
        }
    }.start();
}

ScheduledExecutorService将返回一个Future,它有一个额外的方法来检查Runnable是否完成.两者都有取消Runnable的方法.对于像这样的重复任务,检查它是否已完成,可能不会有多大用处.但是,它是用jdk 1.5并发api引入的,它绝对应该用来代替旧的并发/线程api(Timer和TimerTask是jdk 1.3).它们将更强大,性能更好.它们与java doc here中的用例具有非常相似的示例.

这是一个样本：

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

public class ScheduledTaskExample {
    private final ScheduledExecutorService scheduler = Executors
        .newScheduledThreadPool(1);

    public void startScheduleTask() {
    /**
    * not using the taskHandle returned here,but it can be used to cancel
    * the task,or check if it's done (for recurring tasks,that's not
    * going to be very useful)
    */
    final ScheduledFuture<?> taskHandle = scheduler.scheduleAtFixedRate(
        new Runnable() {
            public void run() {
                try {
                    getDataFromDatabase();
                }catch(Exception ex) {
                    ex.printStackTrace(); //or loggger would be better
                }
            }
        },15,TimeUnit.MINUTES);
    }

    private void getDataFromDatabase() {
        System.out.println("getting data...");
    }

    public void shutdowh() {
        System.out.println("shutdown...");
        if(scheduler != null) {
            scheduler.shutdown();
        }
    }

    public static void main(String[] args) {
        final ScheduledTaskExample ste = new ScheduledTaskExample();
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                ste.shutdowh();
            }
        });
        ste.startScheduleTask();

    }
}