Size-limited queue that holds last N elements in Java

最新推荐文章于 2022-03-02 21:10:56 发布

weixin_33994444

最新推荐文章于 2022-03-02 21:10:56 发布

阅读量113

点赞数

CC 4.0 BY-SA版权

文章标签： java

原文链接：http://www.cnblogs.com/mewishu/p/4162858.html

本文探讨了如何在Java中实现一个有限大小的队列，并介绍了Apache Commons Collections库中的CircularFifoQueue类作为替代方案。通过示例代码展示了手动实现的方法，以及如何利用现有库来简化开发。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

A very simple & quick question on Java libraries: is there a ready-made class that implements a Queuewith a fixed maximum size - i.e. it always allows addition of elements, but it will silently remove head elements to accomodate space for newly added elements.

Of course, it's trivial to implement it manually:

import java.util.LinkedList;

public class LimitedQueue<E> extends LinkedList<E> {
    private int limit;

    public LimitedQueue(int limit) {
        this.limit = limit;
    }

    @Override
    public boolean add(E o) {
        super.add(o);
        while (size() > limit) { super.remove(); }
        return true;
    }
}

As far as I see, there's no standard implementation in Java stdlibs, but may be there's one in Apache Commons or something like that?

47 down vote accepted

+50

Apache commons collections 4 has a CircularFifoQueue which is what you are looking for. Quoting the javadoc:

CircularFifoQueue is a first-in first-out queue with a fixed size that replaces its oldest element if full.

If you are using an older version of the Apache commons collections (3.x), you can use theCircularFifoBuffer which is basically the same thing without generics.

Update: updated answer following release of commons collections version 4

转载于:https://www.cnblogs.com/mewishu/p/4162858.html