Regarding Memory Leaks

[sarma kiran]

Am going through the Memory Leaks Concept.

I have come across the below line.

"In Java typically memory leak occurs when an object of longer life cycle has a reference to objects of a short life
cycle."

Can any one explain with some example?

Thanks in advance..

[Campbell Ritchie]

Imagine you have a stack, implemented on an array. You can push objects onto the stack by saying

public void push(Foo f)
{
    stackArray[size++] = f;
}

Then you pop things off the stack like this

public Foo pop()
{
    return stackArray[--size];
}

Then you forget all about the f reference. But you have forgotten that it is still on that array. If you don't push anything else onto the stack, that f reference will stay there for ever. You have no methods allowing access to it, but the JVM still sees it as "reachable." If you find a copy of Joshua Bloch's Effective Java look on page 24 (2nd edition; don't know page for 1st edition) and it gives a much better explanation of the same problem.