Java 8 Streams - 超时？ [英] Java 8 Streams - Timeout?

问题描述

我想循环一个庞大的数组并执行一系列复杂的指令，这需要很长时间。但是，如果超过30秒，我希望它放弃。

I want to loop over a huge array and do a complicated set of instructions that takes a long time. However, if more than 30 seconds have passed, I want it to give up.

前。

final long start = System.currentTimeMillis();
myDataStructure.stream()
    .while(() -> System.currentTimeMillis() <= start + 30000)
    .forEach(e ->
    {
      ...
    });

我想避免在里面说返回如果满足某个条件，则 forEach 调用。

I want to avoid just saying return inside the forEach call if a certain condition is met.

推荐答案

如果迭代与实际执行操作相比，这种情况下的流或数组比使用谓词更便宜，并且过滤时间是否结束。

If iterating the stream or array in this case is cheap compared to actually executing the operation than just use a predicate and filter whether time is over or not.

final long end = System.nanoTime() + TimeUnit.SECONDS.toNanos(30L);
myDataStructure.stream()
    .filter(e -> System.nanoTime() <= end)
    .forEach(e ->
    {
      ...
    });

问题是您是否需要知道哪些元素已被处理。有了上述内容，您必须检查之后是否对特定元素发生了副作用。

Question is if you need to know which elements have been processed or not. With the above you have to inspect whether a side effect took place for a specific element afterwards.

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