akr的用法

AAR is one of the main factors that leads to the destruction of concrete constructions.

碱集料反应(AKR)是导致混凝土结构破坏的重要原因之一.

The Entry type, which is used to store the key-value mapping, extends WeakReference, so when expungeStaleEntries() asks for the next expired weak reference, it gets back an Entry.

用于存储键-值映射的Entry类型扩展了WeakReference，因此当expungeStaleEntries（）要求下一个失效的弱引用时，它得到一个Entry。

If the weak reference has been cleared ( either because the referent has already been garbage collected or because someone called WeakReference. clear()), get() returns null.

如果弱引用被清除了（不管是referent已经被垃圾收集了，还是有人调用了WeakReference.clear（）），get（）会返回null。