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Finalize

If an object has a finalize() method, the JVM will invoke it just before the object is garbage collected.

protected void finalize() {
  System.out.println("finalize called");
}

Since garbage collection may never run, don't count on finalize to free resources you need back, like open files or database connections.

  • Calling finalize does not cause an object to be garbage-collected.

  • Its purpose is to give an object a last chance to prepare itself before being garbage-collected, which in fact may never happen.

If the garbage collector calls finalize on an object but fails to garbage collect that object, it will not call finalize again.

Practice Exercise

You won't use finalize much in real projects. Some programmers follow the convention of creating a dispose() method, which they call explicitly when they're done with an object.

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