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本篇文章給大家分享的是有關(guān)如何正確的使用jdk定時器，小編覺得挺實用的，因此分享給大家學(xué)習(xí)，希望大家閱讀完這篇文章后可以有所收獲，話不多說，跟著小編一起來看看吧。
首先看一下jdk自帶定時器：
一種工具，線程用其安排以后在后臺線程中執(zhí)行的任務(wù)?？砂才湃蝿?wù)執(zhí)行一次，或者定期重復(fù)執(zhí)行。與每個 Timer 對象相對應(yīng)的是單個后臺線程，用于順序地執(zhí)行所有計時器任務(wù)。計時器任務(wù)應(yīng)該迅速完成。如果完成某個計時器任務(wù)的時間太長，那么它會“獨占”計時器的任務(wù)執(zhí)行線程。因此，這就可能延遲后續(xù)任務(wù)的執(zhí)行，而這些任務(wù)就可能“堆在一起”，并且在上述不友好的任務(wù)最終完成時才能夠被快速連續(xù)地執(zhí)行。
schedule(TimerTask task,long delay) 安排在指定延遲后執(zhí)行指定的任務(wù)。
schedule(TimerTask task,Date time) 安排在指定的時間執(zhí)行指定的任務(wù)。如果此時間已過去，則安排立即執(zhí)行該任務(wù)。
schedule(TimerTask task, long delay, long period) 安排指定的任務(wù)從指定的延遲后開始進(jìn)行重復(fù)的固定延遲執(zhí)行。如果由于任何原因（如垃圾回收或其他后臺活動）而延遲了某次執(zhí)行，則后續(xù)執(zhí)行也將被延遲
schedule(TimerTask task,Date firstTime,long period) 安排指定的任務(wù)在指定的時間開始進(jìn)行重復(fù)的固定延遲執(zhí)行。如果由于任何原因（如垃圾回收或其他后臺活動）而延遲了某次執(zhí)行，則后續(xù)執(zhí)行也將被延遲。
package test;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
/**
* jdk自帶定時器
*
* @author LIUTIE
*
*/
public class JDKTimer {
public static void main(String[] args) throws ParseException {
//日期格式工具
final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Timer timer = new Timer();
// 10s后執(zhí)行定時器，僅執(zhí)行一次
System.out.print(sdf.format(new Date()));
System.out.println("the timer one will be executed after 10 seconds...");
long milliseconds = 10 * 1000;
timer.schedule(new TimerTask() {
@Override
public void run() {
System.out.print(sdf.format(new Date()));
System.out.println("the timer one has finished execution");
}
}, milliseconds);
//12秒后執(zhí)行定時器，每1s執(zhí)行一次
System.out.print(sdf.format(new Date()));
System.out.println("the timer two will be executed after 12 seconds...");
//啟動后延遲時間
long afterSs = 12 * 1000;
//執(zhí)行周期
long intervalSs1 = 1 * 1000;
timer.schedule(new TimerTask() {
// 執(zhí)行計數(shù)器
int i = 0;
@Override
public void run() {
System.out.print(sdf.format(new Date()));
System.out.println("the timer two has execution " + (++i) + " timers");
// 執(zhí)行10次后關(guān)閉定時器
if (i == 10) {
this.cancel();
}
}
}, afterSs, intervalSs1);
// 指定時間執(zhí)行定時器，僅執(zhí)行一次
System.out.print(sdf.format(new Date()));
System.out.println("the timer three will be executed at 2017-06-27 21:47:00...");
Date date = sdf.parse("2017-06-27 21:47:00");
timer.schedule(new TimerTask() {
@Override
public void run() {
System.out.print(sdf.format(new Date()));
System.out.println("the timer three has finished execution");
}
}, date);
// 從指定時間開始周期性執(zhí)行
System.out.print(sdf.format(new Date()));
System.out.println("the timer four will be executed at 2017-06-27 21:48:00...");
// 執(zhí)行間隔周期
long intervalSs = 1 * 1000;
// 開始執(zhí)行時間
Date beginTime = sdf.parse("2017-06-27 21:48:00");
timer.schedule(new TimerTask() {
// 執(zhí)行計數(shù)器
int i = 0;
@Override
public void run() {
System.out.print(sdf.format(new Date()));
System.out.println("the timer four has execution " + (++i) + " timers");
// 執(zhí)行10次后關(guān)閉定時器
if (i == 10) {
this.cancel();
}
}
}, beginTime, intervalSs);
}
}執(zhí)行結(jié)果
2017-06-27 21:46:24the timer one will be executed after 10 seconds... 2017-06-27 21:46:24the timer two will be executed after 12 seconds... 2017-06-27 21:46:24the timer three will be executed at 2017-06-27 21:47:00... 2017-06-27 21:46:24the timer four will be executed at 2017-06-27 21:48:00... 2017-06-27 21:46:34the timer one has finished execution 2017-06-27 21:46:36the timer two has execution 1 timers 2017-06-27 21:46:37the timer two has execution 2 timers 2017-06-27 21:46:38the timer two has execution 3 timers 2017-06-27 21:46:39the timer two has execution 4 timers 2017-06-27 21:46:40the timer two has execution 5 timers 2017-06-27 21:46:41the timer two has execution 6 timers 2017-06-27 21:46:42the timer two has execution 7 timers 2017-06-27 21:46:43the timer two has execution 8 timers 2017-06-27 21:46:44the timer two has execution 9 timers 2017-06-27 21:46:45the timer two has execution 10 timers 2017-06-27 21:47:00the timer three has finished execution 2017-06-27 21:48:00the timer four has execution 1 timers 2017-06-27 21:48:01the timer four has execution 2 timers 2017-06-27 21:48:02the timer four has execution 3 timers 2017-06-27 21:48:03the timer four has execution 4 timers 2017-06-27 21:48:04the timer four has execution 5 timers 2017-06-27 21:48:05the timer four has execution 6 timers 2017-06-27 21:48:06the timer four has execution 7 timers 2017-06-27 21:48:07the timer four has execution 8 timers 2017-06-27 21:48:08the timer four has execution 9 timers 2017-06-27 21:48:09the timer four has execution 10 timers
以上就是如何正確的使用jdk定時器，小編相信有部分知識點可能是我們?nèi)粘９ぷ鲿姷交蛴玫降?。希望你能通過這篇文章學(xué)到更多知識。更多詳情敬請關(guān)注億速云行業(yè)資訊頻道。
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