跳过功能，如果它需要太长时间 [英] Skip function if it takes too long

问题描述

在Java中，我有一个以某种方式处理文本文件的函数。但是，如果花费太多时间，该过程很可能对该文本文件无用（无论什么原因），我想跳过它。此外，如果过程耗时太长，它也会占用太多内存。我试图用这种方式解决它，但它不起作用：

In Java I have a function that processes a text file in a certain way. However, if it takes too much time the process will most likely be useless (whatever the reason is) for that text file and I would like to skip it. Furthermore, if the process takes too long, it also uses too much memory. I've tried to solve it this way, but it doesn't work:

for (int i = 0; i<docs.size(); i++){
    try{
        docs.get(i).getAnaphora();
        }
    catch (Exception e){
        System.err.println(e);
    }
 }

其中 docs 只是目录中文件的列表。通常我必须手动停止代码，因为它卡在特定文件（取决于该文件的内容）。

where docs is just a List of files in a directory. Usually I have to manually stop the code because it is 'stuck' at a particular file (depending on the contents of that file).

有没有办法测量该函数调用的时间，并告诉Java跳过该函数所需的文件，比如10秒？

Is there a way of measuring time for that function call and tell Java to skip the file the function takes more than, let's say, 10 seconds?

编辑

在拼凑出几个不同的答案之后，我想出了这个解决方案，效果很好。也许其他人也可以使用这个想法。

EDIT
After scraping a few different answers together I came up with this solution which works fine. Perhaps someone else can use the idea as well.

首先创建一个实现Runable的类（这样你可以根据需要将参数传递给Thread）：

First create a class that implements Runable (this way you can pass in arguments to the Thread if needed):

public class CustomRunnable implements Runnable {

    Object argument;

    public CustomRunnable (Object argument){
        this.argument = argument;
}

    @Override
    public void run() {
        argument.doFunction();
    }
}

然后在 main 类来监视函数的时间（ argument.doFunction（））并退出，如果它需要很长时间：

Then use this code in the main class to monitor the time of a function (argument.doFunction()) and exit if it takes to long:

Thread thread;
for (int i = 0; i<someObjectList.size(); i++){          
    thread = new Thread(new CustomRunnable(someObjectList.get(i)));
    thread.start();
    long endTimeMillis = System.currentTimeMillis() + 20000;
    while (thread.isAlive()) {
        if (System.currentTimeMillis() > endTimeMillis) {
        thread.stop();
        break;
    }
    try {
        System.out.println("\ttimer:"+(int)(endTimeMillis - System.currentTimeMillis())/1000+"s");
        thread.sleep(2000);
        }
    catch (InterruptedException t) {}
    }
}

我意识到 stop（）已经被删除了，但是当我希望它停止时，我还没有找到任何其他方法来停止和退出该线程。

I realise stop() is depcecated, but I haven't found any other way to stop and exit the thread when I want it to stop.

推荐答案

将代码包装在 Runnable 或 Callable中并将其提交给合适的Executor来执行它。其中一个提交方法需要一段超时时间，之后代码被中断。

Wrap your code in a Runnable or Callable and submit it to a suitable Executor to execute it. One of the submit method takes a timeout period after which has passed the code is interrupted.

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