java 定时任务处理
import java.util.ArrayList; import java.util.List; import java.util.Random; import java.util.concurrent.DelayQueue; import java.util.concurrent.Delayed; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; import static java.util.concurrent.TimeUnit.*; class DelayedTask implements Runnable, Delayed { private static int counter = 0; protected static List<DelayedTask> sequence = new ArrayList<>(); private final int id = counter++; private final int delayTime; private final long triggerTime; public DelayedTask(int delayInMillis) { delayTime = delayInMillis; triggerTime = System.nanoTime() + NANOSECONDS.convert(delayTime, MILLISECONDS); sequence.add(this); } @Override public int compareTo(Delayed o) { DelayedTask that = (DelayedTask)o; return triggerTime < that.triggerTime ? -1 : 1; } /** * 剩余的延迟时间 */ @Override public long getDelay(TimeUnit unit) { return unit.convert(triggerTime - System.nanoTime(), NANOSECONDS); } @Override public void run() { System.out.println(this + " "); } @Override public String toString() { return String.format("[%1$-4d]", delayTime) + " Task " + id; } public static class EndSentinel extends DelayedTask { private ExecutorService exec; public EndSentinel(int delay, ExecutorService exec) { super(delay); this.exec = exec; } @Override public void run() { System.out.println(this + " calling shutDownNow()"); exec.shutdownNow(); } } } class DelayedTaskConsumer implements Runnable { private DelayQueue<DelayedTask> tasks; public DelayedTaskConsumer(DelayQueue<DelayedTask> tasks) { this.tasks = tasks; } @Override public void run() { try { while(!Thread.interrupted()) { tasks.take().run();//run tasks with current thread. } } catch (InterruptedException e) { // TODO: handle exception } System.out.println("Finished DelaytedTaskConsumer."); } } public class DelayQueueDemo { public static void main(String[] args) { int maxDelayTime = 5000;//milliseconds Random random = new Random(47); ExecutorService exec = Executors.newCachedThreadPool(); DelayQueue<DelayedTask> queue = new DelayQueue<>(); //填充10个休眠时间随机的任务 for (int i = 0; i < 10; i++) { queue.put(new DelayedTask(random.nextInt(maxDelayTime))); } //设置结束的时候。 queue.add(new DelayedTask.EndSentinel(maxDelayTime, exec)); exec.execute(new DelayedTaskConsumer(queue)); } }
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Delayed;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import static java.util.concurrent.TimeUnit.*;
class DelayedTask implements Runnable, Delayed {
private static int counter = 0;
protected static List<DelayedTask> sequence = new ArrayList<>();
private final int id = counter++;
private final int delayTime;
private final long triggerTime;
public DelayedTask(int delayInMillis) {
delayTime = delayInMillis;
triggerTime = System.nanoTime() + NANOSECONDS.convert(delayTime, MILLISECONDS);
sequence.add(this);
}
@Override
public int compareTo(Delayed o) {
DelayedTask that = (DelayedTask)o;
return triggerTime < that.triggerTime ? -1 : 1;
}
/**
* 剩余的延迟时间
*/
@Override
public long getDelay(TimeUnit unit) {
return unit.convert(triggerTime - System.nanoTime(), NANOSECONDS);
}
@Override
public void run() {
System.out.println(this + " ");
}
@Override
public String toString() {
return String.format("[%1$-4d]", delayTime) + " Task " + id;
}
public static class EndSentinel extends DelayedTask {
private ExecutorService exec;
public EndSentinel(int delay, ExecutorService exec) {
super(delay);
this.exec = exec;
}
@Override
public void run() {
System.out.println(this + " calling shutDownNow()");
exec.shutdownNow();
}
}
}
class DelayedTaskConsumer implements Runnable {
private DelayQueue<DelayedTask> tasks;
public DelayedTaskConsumer(DelayQueue<DelayedTask> tasks) {
this.tasks = tasks;
}
@Override
public void run() {
try {
while(!Thread.interrupted()) {
tasks.take().run();//run tasks with current thread.
}
} catch (InterruptedException e) {
// TODO: handle exception
}
System.out.println("Finished DelaytedTaskConsumer.");
}
}
public class DelayQueueDemo {
public static void main(String[] args) {
int maxDelayTime = 5000;//milliseconds
Random random = new Random(47);
ExecutorService exec = Executors.newCachedThreadPool();
DelayQueue<DelayedTask> queue = new DelayQueue<>();
//填充10个休眠时间随机的任务
for (int i = 0; i < 10; i++) {
queue.put(new DelayedTask(random.nextInt(maxDelayTime)));
}
//设置结束的时候。
queue.add(new DelayedTask.EndSentinel(maxDelayTime, exec));
exec.execute(new DelayedTaskConsumer(queue));
}
}