MemoryLeak‘s main() method first creates a java.util.ArrayList to store EnclosingClass.EnclosedClass objects. ... which references an array of 100,000 32-bit integers (or 400,000 bytes).

The boxing and unboxing of Java primitive types has severe performance implications. ... If a developer has a set of int values they want to store in an ArrayList, it can’t be done. Unless, of course, ...