Does remove() deletes object?

Question

I'm a self-studying student of java. I've been reading this forum for six months but it's my first time to post a question. This forum have been one of my teachers on java.
Please help me with my problem:
I created a synchornized map myMap with strings as the key and instance of MyClass as the values.
Map myMap = Collections.synchronizedMap(new HashMap());
I used the follwing statement to add values to myMap:
myMap.put(someString, new MyClass());
I used the following statement to remove an element from myMap:
myMap.remove(someString); // note: this removing is always successful
My problem is that I always get OutOfMemoryError and when I check my profiler, the instance of MyClass I created with myMap.put(someString, new MyClass()); is not garbage collected even I have already remove them from myMap.
My question is "does remove() also deletes object?" If it doesn't, please give me some tip on how to delete those objects so that I will no longer get OutOfMemoryError.
Thank you very much.

Answer 1

My question is "does remove() also deletes object?" If
it doesn't, please give me some tip on how to delete
those objects so that I will no longer get
OutOfMemoryError.No. It's about time for you to learn this: the Map doesn't contain any objects. It just contains references to objects. So when you call its remove() method, it removes the reference to the object from the Map. It doesn't "delete" the object itself. Nothing in Java will "delete" an object except for the garbage collector.
And the garbage collector will only remove an object from memory if there is nothing in your program that has a reference to it. The fact that you are running out of memory means that something else, other than the Map, still has references to all those objects. From the code you have posted it's impossible to tell what that might be, but there must be something.