Java Memory Management
JavaBlock — release any Java objects created during evaluation once evaluation finishes
BeginJavaBlock, EndJavaBlock — mark the beginning and end of a Java block
KeepJavaObject — allow a Java object to persist when the current JavaBlock ends
ReleaseJavaObject — finish using a Java object in the Wolfram Language
SameObjectQ — whether two JavaObject expressions reference the same Java object
LoadedJavaObjects, LoadedJavaClasses — list all Java objects or classes in use