Namespace Java.Lang.Ref Classes PhantomReference https://docs.oracle.com/javase/8/docs/api/java/lang/ref/PhantomReference.html PhantomReference<T> https://docs.oracle.com/javase/8/docs/api/java/lang/ref/PhantomReference.html Reference https://docs.oracle.com/javase/8/docs/api/java/lang/ref/Reference.html ReferenceQueue https://docs.oracle.com/javase/8/docs/api/java/lang/ref/ReferenceQueue.html ReferenceQueue<T> https://docs.oracle.com/javase/8/docs/api/java/lang/ref/ReferenceQueue.html Reference<T> https://docs.oracle.com/javase/8/docs/api/java/lang/ref/Reference.html SoftReference https://docs.oracle.com/javase/8/docs/api/java/lang/ref/SoftReference.html SoftReference<T> https://docs.oracle.com/javase/8/docs/api/java/lang/ref/SoftReference.html WeakReference https://docs.oracle.com/javase/8/docs/api/java/lang/ref/WeakReference.html WeakReference<T> https://docs.oracle.com/javase/8/docs/api/java/lang/ref/WeakReference.html