blocks|key|536563|text|使用ScheduledExecutorService|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|536564|+private+final+ScheduledExecutorService+scheduler+=+Executors.newScheduledThreadPool(1);
+scheduler.scheduleAtFixedRate(yourRunnable,+8,+8,+TimeUnit.HOURS);|code-block|syntax|javascript|536565|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/concurrent/ScheduledExecutorService.html^0|2|O|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

Use a <a href="http://download.oracle.com/javase/6/docs/api/java/util/concurrent/ScheduledExecutorService.html">ScheduledExecutorService</a>:

<pre><code> private final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
 scheduler.scheduleAtFixedRate(yourRunnable, 8, 8, TimeUnit.HOURS);
</code></pre>

blocks|key|753047|text|您应该看看Quartz，它是一个java框架，可以与EE和SE版本协同工作，并允许定义作业在特定时间执行|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|753048|entityMap|0|LINK|mutability|MUTABLE|url|http://www.quartz-scheduler.org/^0|5|6|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

You should take a look to <a href="http://www.quartz-scheduler.org/">Quartz</a> it's a java framework wich works with EE and SE editions and allows to define jobs to execute an specific time

blocks|key|753184|text|试试这个方法->|type|unstyled|depth|inlineStyleRanges|entityRanges|data|753185|首先创建一个运行任务的类TimeTask，如下所示：|753186|public+class+CustomTask+extends+TimerTask++{

+++public+CustomTask(){

+++++//Constructor

+++}

+++public+void+run()+{
+++++++try+{

+++++++++//+Your+task+process

+++++++}+catch+(Exception+ex)+{
+++++++++++System.out.println("error+running+thread+"+%2B+ex.getMessage());
+++++++}
++++}
}|code-block|syntax|javascript|753187|然后，在main类中，实例化任务并定期运行指定日期开始的任务：|753188|+public+void+runTask()+{

++++++++Calendar+calendar+=+Calendar.getInstance();
++++++++calendar.set(
+++++++++++Calendar.DAY_OF_WEEK,
+++++++++++Calendar.MONDAY
++++++++);
++++++++calendar.set(Calendar.HOUR_OF_DAY,+15);
++++++++calendar.set(Calendar.MINUTE,+40);
++++++++calendar.set(Calendar.SECOND,+0);
++++++++calendar.set(Calendar.MILLISECOND,+0);



++++++++Timer+time+=+new+Timer();+//+Instantiate+Timer+Object

++++++++//+Start+running+the+task+on+Monday+at+15:40:00,+period+is+set+to+8+hours
++++++++//+if+you+want+to+run+the+task+immediately,+set+the+2nd+parameter+to+0
++++++++time.schedule(new+CustomTask(),+calendar.getTime(),+TimeUnit.HOURS.toMillis(8));
}|753189|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Try this way ->

Firstly create a class TimeTask that run your task, it looks like:

<pre><code>public class CustomTask extends TimerTask {

 public CustomTask(){

 //Constructor

 }

 public void run() {
 try {

 // Your task process

 } catch (Exception ex) {
 System.out.println("error running thread " + ex.getMessage());
 }
 }
}
</code></pre>

then in main class you instantiate the task and run it periodically started by a specified date:

<pre><code> public void runTask() {

 Calendar calendar = Calendar.getInstance();
 calendar.set(
 Calendar.DAY_OF_WEEK,
 Calendar.MONDAY
 );
 calendar.set(Calendar.HOUR_OF_DAY, 15);
 calendar.set(Calendar.MINUTE, 40);
 calendar.set(Calendar.SECOND, 0);
 calendar.set(Calendar.MILLISECOND, 0);



 Timer time = new Timer(); // Instantiate Timer Object

 // Start running the task on Monday at 15:40:00, period is set to 8 hours
 // if you want to run the task immediately, set the 2nd parameter to 0
 time.schedule(new CustomTask(), calendar.getTime(), TimeUnit.HOURS.toMillis(8));
}
</code></pre>

blocks|key|536691|text|使用谷歌Guava+AbstractScheduledService，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|536692|public+class+ScheduledExecutor+extends+AbstractScheduledService+{

+++@Override
+++protected+void+runOneIteration()+throws+Exception+{
++++++System.out.println("Executing....");
+++}

+++@Override
+++protected+Scheduler+scheduler()+{
++++++++return+Scheduler.newFixedRateSchedule(0,+3,+TimeUnit.SECONDS);
+++}

+++@Override
+++protected+void+startUp()+{
+++++++System.out.println("StartUp+Activity....");
+++}


+++@Override
+++protected+void+shutDown()+{
+++++++System.out.println("Shutdown+Activity...");
+++}

+++public+static+void+main(String[]+args)+throws+InterruptedException+{
+++++++ScheduledExecutor+se+=+new+ScheduledExecutor();
+++++++se.startAsync();
+++++++Thread.sleep(15000);
+++++++se.stopAsync();
+++}
}|code-block|syntax|javascript|536693|如果你有更多这样的服务，那么在ServiceManager中注册所有服务将是很好的，因为所有服务都可以一起启动和停止。有关ServiceManager的更多信息，请阅读here。|536694|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/google/guava/wiki/ServiceExplained^0|A|O|0|0|2C|4|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

Use Google Guava <code>AbstractScheduledService</code> as given below:
<pre><code>public class ScheduledExecutor extends AbstractScheduledService {

 @Override
 protected void runOneIteration() throws Exception {
 System.out.println(&quot;Executing....&quot;);
 }

 @Override
 protected Scheduler scheduler() {
 return Scheduler.newFixedRateSchedule(0, 3, TimeUnit.SECONDS);
 }

 @Override
 protected void startUp() {
 System.out.println(&quot;StartUp Activity....&quot;);
 }


 @Override
 protected void shutDown() {
 System.out.println(&quot;Shutdown Activity...&quot;);
 }

 public static void main(String[] args) throws InterruptedException {
 ScheduledExecutor se = new ScheduledExecutor();
 se.startAsync();
 Thread.sleep(15000);
 se.stopAsync();
 }
}
</code></pre>
If you have more services like this, then registering all services in ServiceManager will be good as all services can be started and stopped together. Read <a href="https://github.com/google/guava/wiki/ServiceExplained" rel="nofollow noreferrer">here</a> for more on ServiceManager.

blocks|key|753106|text|如果您想坚持使用java.util.Timer，您可以使用它来安排较大的时间间隔。您只需传递您要争取的时间段。请查看文档here。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|753107|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/Timer.html^0|8|F|1O|4|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

If you want to stick with <code>java.util.Timer</code>, you can use it to schedule at large time intervals. You simply pass in the period you are shooting for. Check the documentation <a href="http://download.oracle.com/javase/6/docs/api/java/util/Timer.html" rel="noreferrer">here</a>.

blocks|key|536781|text|每一秒做一件事|type|unstyled|depth|inlineStyleRanges|entityRanges|data|536782|Timer+timer+=+new+Timer();
timer.schedule(new+TimerTask()+{
++++@Override
++++public+void+run()+{
++++++++//code
++++}
},+0,+1000);|code-block|syntax|javascript|536783|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Do something every one second

<pre class="lang-java prettyprint-override"><code>Timer timer = new Timer();
timer.schedule(new TimerTask() {
 @Override
 public void run() {
 //code
 }
}, 0, 1000);
</code></pre>

blocks|key|753298|text|如果您的应用程序已经在使用Spring框架，那么您就拥有内置的Scheduling|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|753299|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.spring.io/spring/docs/current/spring-framework-reference/html/scheduling.html^0|V|A|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

If your application is already using Spring framework, you have <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html/scheduling.html" rel="noreferrer">Scheduling</a> built in

blocks|key|536836|text|这两个类可以协同工作来调度定期任务：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|536837|计划任务|536838|import+java.util.TimerTask;
import+java.util.Date;

//+Create+a+class+extending+TimerTask
public+class+ScheduledTask+extends+TimerTask+{
++++Date+now;+
++++public+void+run()+{
++++++++//+Write+code+here+that+you+want+to+execute+periodically.
++++++++now+=+new+Date();++++++++++++++++++++++//+initialize+date
++++++++System.out.println("Time+is+:"+%2B+now);+//+Display+current+time
++++}
}|code-block|syntax|javascript|536839|运行计划任务|536840|import+java.util.Timer;

public+class+SchedulerMain+{
++++public+static+void+main(String+args[])+throws+InterruptedException+{
++++++++Timer+time+=+new+Timer();+++++++++++++++//+Instantiate+Timer+Object
++++++++ScheduledTask+st+=+new+ScheduledTask();+//+Instantiate+SheduledTask+class
++++++++time.schedule(st,+0,+1000);+++++++++++++//+Create+task+repeating+every+1+sec
++++++++//for+demo+only.
++++++++for+(int+i+=+0;+i+<=+5;+i%2B%2B)+{
++++++++++++System.out.println("Execution+in+Main+Thread...."+%2B+i);
++++++++++++Thread.sleep(2000);
++++++++++++if+(i+==+5)+{
++++++++++++++++System.out.println("Application+Terminates");
++++++++++++++++System.exit(0);
++++++++++++}
++++++++}
++++}
}|536841|参考https://www.mkyong.com/java/how-to-run-a-task-periodically-in-java/|offset|length|536842|entityMap|0|LINK|mutability|MUTABLE|url|https://www.mkyong.com/java/how-to-run-a-task-periodically-in-java/^0|0|0|0|0|0|2|1V|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|13|8|@]|9|@$O|14|P|15|1|16]]|A|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

These two classes can work together to schedule a periodic task:

<h2>Scheduled Task</h2>

<pre><code>import java.util.TimerTask;
import java.util.Date;

// Create a class extending TimerTask
public class ScheduledTask extends TimerTask {
 Date now; 
 public void run() {
 // Write code here that you want to execute periodically.
 now = new Date(); // initialize date
 System.out.println("Time is :" + now); // Display current time
 }
}
</code></pre>

<h2>Run Scheduled Task</h2>

<pre><code>import java.util.Timer;

public class SchedulerMain {
 public static void main(String args[]) throws InterruptedException {
 Timer time = new Timer(); // Instantiate Timer Object
 ScheduledTask st = new ScheduledTask(); // Instantiate SheduledTask class
 time.schedule(st, 0, 1000); // Create task repeating every 1 sec
 //for demo only.
 for (int i = 0; i &lt;= 5; i++) {
 System.out.println("Execution in Main Thread...." + i);
 Thread.sleep(2000);
 if (i == 5) {
 System.out.println("Application Terminates");
 System.exit(0);
 }
 }
 }
}
</code></pre>

Reference <a href="https://www.mkyong.com/java/how-to-run-a-task-periodically-in-java/" rel="noreferrer">https://www.mkyong.com/java/how-to-run-a-task-periodically-in-java/</a>

blocks|key|536878|text|我的servlet包含以下代码:如果用户按下accept，如何将其保留在调度程序中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|536879|if(bt.equals("accept"))+{
++++ScheduledExecutorService+scheduler=Executors.newScheduledThreadPool(1);
++++String+lat=request.getParameter("latlocation");
++++String+lng=request.getParameter("lnglocation");
++++requestingclass.updatelocation(lat,lng);
}|code-block|syntax|javascript|536880|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

my servlet contains this as a code how to keep this in scheduler if a user presses accept

<pre class="lang-java prettyprint-override"><code>if(bt.equals("accept")) {
 ScheduledExecutorService scheduler=Executors.newScheduledThreadPool(1);
 String lat=request.getParameter("latlocation");
 String lng=request.getParameter("lnglocation");
 requestingclass.updatelocation(lat,lng);
}
</code></pre>

blocks|key|753469|text|在java.util.concurrent中有一个ScheduledFuture类，它可能会对你有所帮助。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|753470|entityMap^0|P|F|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

There is a <code>ScheduledFuture</code> class in java.util.concurrent, it may helps you.

I need to schedule a task to run in at fixed interval of time. How can I do this with support of long intervals (for example on each 8 hours)?

I'm currently using <code>java.util.Timer.scheduleAtFixedRate</code>. Does <code>java.util.Timer.scheduleAtFixedRate</code> support long time intervals?

How to schedule a periodic task in Java?

我需要安排一个任务以固定的时间间隔运行。我如何在支持长时间间隔(例如每8小时)的情况下做到这一点？我目前使用的是java.util.Timer.scheduleAtFixedRate。java.util.Timer.scheduleAtFixedRate是否支持长时间间隔？

问如何在Java中调度周期性任务？
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