如何在不使用setTimeout的情况下异步运行javascript函数？

Question

其服务器端JavaScript（犀牛引擎），所以setTimeout不可用。如何异步运行一个函数？

Answer 1

查看Rhino Examples页面上的Multithreaded Script Execution示例。基本上，JavaScript不直接支持线程，但您可以使用Java线程来实现您正在寻找的内容。

Answer 2

您可以使用java.util.Timer和java.util.TimerTask推出自己的设置/清除超时，并设置/清除间隔功能：

var setTimeout, 
    clearTimeout, 
    setInterval, 
    clearInterval; 

(function() { 
    var timer = new java.util.Timer(); 
    var counter = 1; 
    var ids = {}; 

    setTimeout = function (fn,delay) { 
     var id = counter++; 
     ids[id] = new JavaAdapter(java.util.TimerTask,{run: fn}); 
     timer.schedule(ids[id],delay); 
     return id; 
    } 

    clearTimeout = function (id) { 
     ids[id].cancel(); 
     timer.purge(); 
     delete ids[id]; 
    } 

    setInterval = function (fn,delay) { 
     var id = counter++; 
     ids[id] = new JavaAdapter(java.util.TimerTask,{run: fn}); 
     timer.schedule(ids[id],delay,delay); 
     return id; 
    } 

    clearInterval = clearTimeout; 

})() 

Answer 3

使用ScheduledThreadPoolExecutor，犀牛1.7R4兼容，并提出了另一个版本的@Nikita-Beloglazov：

var setTimeout, clearTimeout, setInterval, clearInterval; 

(function() { 
    var executor = new java.util.concurrent.Executors.newScheduledThreadPool(1); 
    var counter = 1; 
    var ids = {}; 

    setTimeout = function (fn,delay) { 
     var id = counter++; 
     var runnable = new JavaAdapter(java.lang.Runnable, {run: fn}); 
     ids[id] = executor.schedule(runnable, delay, 
      java.util.concurrent.TimeUnit.MILLISECONDS); 
     return id; 
    } 

    clearTimeout = function (id) { 
     ids[id].cancel(false); 
     executor.purge(); 
     delete ids[id]; 
    } 

    setInterval = function (fn,delay) { 
     var id = counter++; 
     var runnable = new JavaAdapter(java.lang.Runnable, {run: fn}); 
     ids[id] = executor.scheduleAtFixedRate(runnable, delay, delay, 
      java.util.concurrent.TimeUnit.MILLISECONDS); 
     return id; 
    } 

    clearInterval = clearTimeout; 

})() 

参考：https://gist.github.com/nbeloglazov/9633318