Question

What is the difference between Final, Finally, and finalize?

final

is a keyword.

1. Variable decleared as final should be initialized only once and cannot be changed.
2. Classes declared as final cannot be extended.
3. Methods declared as final cannot be overridden.

Code:

private final String name = "foo";

public final String toString() {  return "NULL"; }

// final can also make a class not "inheritable"
public final class finalClass {...}
public class classNotAllowed extends finalClass {...} 
// Not allowed

finally

is a block.

The finally block always executes when the try block exits (even if an unexpected exception occurs).

lock.lock();
try {
    //do stuff
} catch (SomeException se) {
    //handle se
} finally {
    lock.unlock(); //always executed, even if Exception or Error or se
}

finalize

is a method.

It’s called by Garbage Collector before reclaiming GC eligible objects.

public void finalize() {
    //free resources (e.g. unallocate memory)
    super.finalize();
}

source1

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