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弱引用中的强引用

[英]Strong references within weak references

原文 2011-03-15 19:28:20 8 2 java/ memory/ weak-references

in Java, are strong references accessible from weakly reachable objects are considered as strong references? 在Java中，可从弱可达对象访问的强引用是否被视为强引用？

Example : 示例：

I can access X by a weak reference. 我可以通过弱引用来访问X.
I can access Y by a weak reference. 我可以通过弱引用来访问Y.
I can access X by a pointer from Y. 我可以通过Y的指针访问X.
I can access Y by a pointer from X. 我可以通过X的指针访问Y.

If there is no other pointer on X and Y, I would expect them to get garbage-collected. 如果X和Y上没有其他指针，我会期望它们被垃圾收集。 Am I wrong? 我错了吗？

2 个解决方案

Even though the term strong reference is used, perhaps it is better to think in terms of reach-ability . 即使使用强引用这一术语，也许最好从达到能力的角度进行思考。

That is, if the object is strongly reachable from a root object it is not eligibility for reclamation -- otherwise, it is. 也就是说，如果从根对象可以很容易地访问该对象，则它不具备回收的资格 - 否则就是。 A strong reference to an object only referenced through a weak reference is not strongly reachable . 强引用到只有通过弱引用引用的对象不是强可到达 。 However, the strong reference is still a strong reference. 但是，强烈的参考仍然是一个强有力的参考。

Happy coding. 快乐的编码。

Both objects may be garbage-collected; 两个对象都可能被垃圾收集; a strong reference from a weakly-referenced object counts as a weak reference. 来自弱引用对象的强引用被视为弱引用。