What is finalize method in java?

Answer 1

Finalize method is used when a variable becomes unreachable or of no use.

it is finalize and garbage collection will free the memory used by it, which can be then reclaimed for some other variable

Answer 2

The final keyword prevents a method from being overridden in a subclass. Final methods are usually placed in classes where you don't want anyone who is extending your code to meddle with a certain piece of functionality. For ex: the Thread class has a method called isAlive() that checks whether a thread is still active. If you extend the Thread class, there is no way that you can correctly implement this method yourself, so the men who coded Java have made it final. Just like you can't subclass the String class (remember the Exercise in the final classes section), you can't override many of the methods in the core class libraries. This can't-be-overridden restriction provides for safety and security, but you should use it with great caution. Preventing a subclass from overriding a method greatly affects many of the benefits of OO including extensibility through polymorphism.

A typical final method declaration looks like this:

public class FinalMethodExampleClass{

public final void youCannotOverrideMe() {

System.out.println("One.");

}

}

It's legal to extend FinalMethodExampleClass, since the class isn't marked final, but we can't override the final method youCannotOverrideMe (), as the following code attempts to do:

class SubClass extends FinalMethodExampleClass {

public void youCannotOverrideMe () {

System.out.println("Two.");

}

}

Attempting to compile the preceding code gives us something like this:

The method void youCannotOverrideMe() declared in class

SubClass cannot override the final method of the same signature

declared in class SuperClass.

Final methods cannot be overridden.

public void youCannotOverrideMe() { }

1 error