java - Java 延迟/等待

Question

如何将 while 循环延迟到 1 秒间隔，而不会将其运行的整个代码/计算机减慢到 1 秒延迟（只是一个小循环）。

Answer 1

Thread.sleep(1000); // do nothing for 1000 miliseconds (1 second)

Answer 2

似乎您的循环在主线程上运行，如果您sleep在该线程上执行，它将暂停应用程序（因为只有一个线程已暂停），为了克服这个问题，您可以将此代码放入Thread并行运行的新代码中

try{

  Thread.sleep(1000);
}catch(InterruptedException ex){
  //do stuff
}

Answer 3

我延迟循环的简单方法。

在未能遵循 stackoverflow 的标准后，我已经将代码放在这里。

//1st way: Thread.sleep : Less efficient compared to 2nd
try {
  while (true) {//Or any Loops
   //Do Something
   Thread.sleep(sleeptime);//Sample: Thread.sleep(1000); 1 second sleep
  }
 } catch (InterruptedException ex) {
   //SomeFishCatching
 }
//================================== Thread.sleep


//2nd way: Object lock waiting = Most efficient due to Object level Sync.
Object obj = new Object();
 try {
  synchronized (obj) {
   while (true) {//Or any Loops
   //Do Something
   obj.wait(sleeptime);//Sample obj.wait(1000); 1 second sleep
   }
  }
 } catch (InterruptedException ex) {
   //SomeFishCatching
 }
//=============================== Object lock waiting

//3rd way:  Loop waiting = less efficient but most accurate than the two.
long expectedtime = System.currentTimeMillis();
while (true) {//Or any Loops
   while(System.currentTimeMillis() < expectedtime){
     //Empty Loop   
   }
   expectedtime += sleeptime;//Sample expectedtime += 1000; 1 second sleep
   //Do Something
}
//===================================== Loop waiting

Answer 4

正如 Jigar 所指出的，您可以使用另一个线程来完成可以独立于其他线程运行、睡眠等的工作。该类java.util.Timer也可能对您有所帮助，因为它可以为您执行定期任务，而无需您进行多线程编程。