java.lang.ref
Interfaces
| Cleanable | 
             
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Classes
| Cleaner | 
             
  | 
        
| PhantomReference | 
             Phantom reference objects, which are enqueued after the collector determines that their referents may otherwise be reclaimed.  | 
        
| Reference | 
             Abstract base class for reference objects.  | 
        
| ReferenceQueue | 
             Reference queues, to which registered reference objects are appended by the garbage collector after the appropriate reachability changes are detected.  | 
        
| SoftReference | 
             Soft reference objects, which are cleared at the discretion of the garbage collector in response to memory demand.  | 
        
| WeakReference | 
             Weak reference objects, which do not prevent their referents from being made finalizable, finalized, and then reclaimed.  |