Is there something like malloc/free in java?

I've never seen such stat开发者_运维知识库ements though,does it exist in java world at all?

Java's version of malloc is new -- it creates a new object of a specified type.

In Java, memory is managed for you, so you cannot explicitly delete or free an object.

Java has a garbage collector. That's why you never see such statements in your code(which is nice if you ask me)

In computer science, garbage collection (GC) is a form of automatic memory management. It is a special case of resource management, in which the limited resource being managed is memory. The garbage collector, or just collector, attempts to reclaim garbage, or memory occupied by objects that are no longer in use by the program. Garbage collection was invented by John McCarthy around 1959 to solve problems in Lisp.

new instead of malloc, garbage collector instead of free.

No direct equivalents exist in Java:

C malloc creates an untyped heap node and returns you a pointer to it that allows you to access the memory however you want.

Java does not have the concept of an untyped object, and does not allow you to access memory directly. The closest that you can get in Java to malloc would be new byte[size], but that returns you a strongly typed object that you can ONLY use as a byte array.

C free releases a heap node.

Java does not allow you to explicitly release objects. Object deallocation in Java is totally in the hands of the garbage collector. In some cases you can influence the behaviour of the GC; e.g. by assigning null to a reference variable and calling System.gc(). However, this does not force the object to be deallocated ... and is a very expensive way to proceed.

If you are up to no good (tm) I suppose you can get access to raw memory though the JNI interface. This is where you can call C programs from Java Programs. Of course you have to be running in an environment where your program has the privileges to do so (a browser won't normally allow this unless it is suicidal) but you can access objects via C pointers that way.

I sort of wonder where the original question is coming from. At one point long ago I was totally skeptical of the notion that C-style memory management and C-style pointers were not needed, but at this point I am true believer.