Hello..need help on topic finalize()

[Supriya Nimakuri]

I couldnot understand finalize() method...

I mean...finalize() will be called only once in a program and finalize() can actually result in saving an objects fron deletion..

How can it save from delletion..can you pllease help me ....

[Naseem Khan]

finalize() method is invoked by JVM internally wen an object is ready 4 gc.

finalize() method is defined in Object class and it is called only once jst before the destruction of the object frm the heap. Its performs a sort of cleapup operation. If an object is using certain resource, so before destroying the object u can free those resources by suitable code in finalize method.

regards

Naseem.K

[Supriya Nimakuri]

Thanks for explanation...can it be explained with an example so tht i can understand better..

[Vikram Kohli]

one more thing, it is not always called for each Object . As it may happen that the program ends and still some Objects are to be GC by JVM.

[S Thiyanesh]

In this code compare the output inside finalize and main
Try to run this multiple times with different timeout, if you don't get any output as you can't predict the behavior of GC.

import java.util.*;
class Sample{   
    static List<Sample> list = new ArrayList<Sample>();    
    int i;
    
    Sample(int i){
        this.i =i;
    }
            
    public void finalize(){
        System.out.println("Finalizing " + this);
        list.add(this);
    }
        
    public static void main(String... vargs) throws InterruptedException{
        Sample s1 = new Sample(10);
        Sample s2 = new Sample(20);
        s1 = null;
        s2 = null;
        System.gc();
        Thread.sleep(1000);
        for(Sample s : list) {
            System.out.println(s + " " + s.i);
        }
    }
}

[ June 08, 2006: Message edited by: S Thiyanesh ]

[Naseem Khan]

Check this thread