package com.aps.common.core.enums;
|
|
import java.sql.Timestamp;
|
import java.util.concurrent.ScheduledExecutorService;
|
import java.util.concurrent.ScheduledThreadPoolExecutor;
|
import java.util.concurrent.TimeUnit;
|
import java.util.concurrent.atomic.AtomicLong;
|
|
/**
|
* System Clock
|
* <p>
|
* 利用ScheduledExecutorService实现高并发场景下System.curentTimeMillis()的性能问题的优化.
|
*
|
* @author lry
|
*/
|
public enum SystemClock {
|
|
// ====
|
|
INSTANCE(1);
|
|
private final long period;
|
private final AtomicLong nowTime;
|
private boolean started = false;
|
private ScheduledExecutorService executorService;
|
|
SystemClock(long period) {
|
this.period = period;
|
this.nowTime = new AtomicLong(System.currentTimeMillis());
|
}
|
|
/**
|
* The initialize scheduled executor service
|
*/
|
public void initialize() {
|
if (started) {
|
return;
|
}
|
|
this.executorService = new ScheduledThreadPoolExecutor(1, r -> {
|
Thread thread = new Thread(r, "system-clock");
|
thread.setDaemon(true);
|
return thread;
|
});
|
executorService.scheduleAtFixedRate(() -> nowTime.set(System.currentTimeMillis()),
|
this.period, this.period, TimeUnit.MILLISECONDS);
|
Runtime.getRuntime().addShutdownHook(new Thread(this::destroy));
|
started = true;
|
}
|
|
/**
|
* The get current time milliseconds
|
*
|
* @return long time
|
*/
|
public long currentTimeMillis() {
|
return started ? nowTime.get() : System.currentTimeMillis();
|
}
|
|
/**
|
* The get string current time
|
*
|
* @return string time
|
*/
|
public String currentTime() {
|
return new Timestamp(currentTimeMillis()).toString();
|
}
|
|
/**
|
* The destroy of executor service
|
*/
|
public void destroy() {
|
if (executorService != null) {
|
executorService.shutdown();
|
}
|
}
|
|
}
|
