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This article will explain in detail how to use Queue for Java collection source code analysis. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.

Super interface Queue

Queue plays an important role in software development. Stack technology is used to call java function. When dealing with concurrency problems, BlockingQueue solves the problem of data transmission very well. Let's take a look at how Java defines queues.

First, Queue also inherits from Collection, indicating that it is a member of the collection family. The Queue API mainly provides the following methods:

/ / insert the element into the queue boolean add (E e); / / insert the element into the queue, compared with add, this boolean offer (E e) should be used when the capacity is limited; / / delete the element at the head of the queue, and throw an exception E remove () if the queue is empty; / / delete the element at the head of the queue, and return nullE poll () if the queue is empty; / / get the element at the head of the queue, but do not remove it, and throw an exception E element () if the queue is empty / / gets the first element of the queue, but does not remove it. If the queue is empty, nullE peek () is returned. The super implementation class AbstractQueue

The definition of Queue is very simple, so its implementation class is also very simple, and it is worth learning to do complex things with simple code.

AbstractQueue only implements three methods: add, remove and element, and calls another method that is only slightly different. Let's just look at one of them here.

/ / here we understand that for those with limited capacity, calling offer directly will certainly be faster public boolean add (E) {if (offer (e)) return true; else throw new IllegalStateException ("Queue full");}

In addition, it implements clear and addAll methods, which can be overridden to make them more in line with the current scene.

Public void clear () {while (poll ()! = null);} public boolean addAll (Collection

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