我需要在爪哇睡很长时间(几天)。

如果您的Java应用程序打算连续运行,那么您可以使用 Timer 按计划执行的类

如果你的应用程序不能持续运行,那么其他答案是正确的。cron/task scheduler是一个不错的选择。

在UNIX上,查看系统工具 cron 或 at .

在Windows上,系统设置中有一个作业调度程序。

对于一个简单的Java解决方案,请尝试 Timer API .

对于更复杂的Java唯一解决方案,请参见 quartz .

如果你需要你的应用在特定时间运行,你可以安排一个cron作业。或者,您可以编写一个简单的类,它将在特定的时间内调度自己。因为我不知道外面有什么图书馆(从来没有真正需要找),我很久以前就写了一个班为自己安排一个任务。希望它能有所帮助,在棒球场:

import java.util.*;

public abstract class TimeMonitor extends Thread
    {
        protected double execution_time;
        protected boolean execute_at_startup;

        public TimeMonitor()
            {
                execute_at_startup = false;
            }

        public TimeMonitor(double time)
            {
                execution_time = time;
                execute_at_startup = false;
            }

        public void startTimer()
            {
                setPriority(Thread.MIN_PRIORITY);
                start();
            }

        public void setTime(double time)
            {
                execution_time = time;
            }

        public void executeAtStartup()
            {
                execute_at_startup = true;
            }

        public void run()
            {
                if (execute_at_startup)
                    doTimedAction();

                while (true)
                    {
                        long runtime = (long)(execution_time * 3600 * 1000);
                        long now     = getTime();
                        long sleep   = 0;

                        // Calculate how long to way until first run
                        if (runtime > now)
                            sleep = runtime - now;
                        else
                            sleep = 24 * 3600 * 1000 - now + runtime;

                        try
                            {
                                Thread.sleep(sleep);
                            }
                        catch (InterruptedException e)
                            {
                                logError("Wait thread has been interrupted.", e);
                                continue;
                            }

                        doTimedAction();
                    }
            }

        /**
         * Calculates number of milliseconds from start of the day.
         *
         * @return Number of milliseconds.
         */
        private long getTime()
            {
                Calendar cal = Calendar.getInstance();
                int hours   = cal.get(Calendar.HOUR_OF_DAY);
                int minutes = cal.get(Calendar.MINUTE);
                int seconds = cal.get(Calendar.SECOND);
                int millis  = cal.get(Calendar.MILLISECOND);

                return (hours * 3600 + minutes * 60 + seconds) * 1000 + millis;
            }

        private void doTimedAction()
            {
                try
                    {
                        performAction();
                    }
                catch (Throwable e)
                    {
                        logError("An error occured during timed execution.", e);
                    }
            }

        /**
         * This method will be called when an error or a warning occures.
         *
         * @param msg
         * @param e
         */
        protected void logError(String msg, Throwable e)
            {
                System.out.println(msg);
                e.printStackTrace();
            }

        /**
         * Action to be performed when scheduled time happens.
         */
        protected abstract void performAction();
    }

扩展到这样的用途:

        TimeMonitor archiver = new TimeMonitor()
            {
                protected void performAction()
                    {
                        // Do the task
                    }
            };

        archiver.setTime(16.5); // Run at 4:30pm
        archiver.startTimer();

Quartz 适合这种类型的东西。它是 supported well in Spring 还有应用程序。

编写Windows服务(或Linux设备的守护程序)

以下是一些链接,可以帮助您开始:

• Running Java Applications as a Windows Service
• Converting Your Java App into a Windows Service
• How to run a Java Program as a daemon (service) on Linux
• How do I run a Java program as a daemon on Linux?

只需使用java.util.concurrent,它就有一个预定的执行小部件。您需要添加一个保护条件来防止过度运行,或者在当前运行结束时添加下一个执行。