Passing Objects to methods, why aren't they changed permanently?

Question

If an object is passed by reference, and primitive types are passed by value; then why does the following programme not alter the original values of A and B?
I m trying to pass parameters into a method so that they can be altered and returned, can any one suggest a way to do this.
Thanks,
Ben.
public class Application2 {
Application2(){ }
     void goProc(){
          Integer A=new Integer(4);
          Integer B=new Integer(6);
          add(A,B);
          System.out.println("A2 " + A);
          System.out.println("B2 " + B);
     void add(Integer A,Integer B){
          System.out.println("A " + A);
          System.out.println("B " + B);
          A=A.valueOf(String.valueOf((A.intValue()+B.intValue())));
          System.out.println("added " + A);
//Main method
     public static void main(String[] args) {
          Application2 App = new Application2();
          Integer A=new Integer(4);
          Integer B=new Integer(1);
          App.add(A,B);
          System.out.println("A1 " + A);
          System.out.println("B1 " + B);
          App.goProc();
OUTPUT.
A 4
B 1
added 5
A1 4
B1 1
A 4
B 6
added 10
A2 4
B2 6

Answer 1

If an object is passed by reference,It isn't. Instead, a pointer to the object is passed
by value.That is exactly what passing by reference is.
Objects passed by reference can be modified and it will affect the caller, but modifying the reference (assiging a new object) won't affect the caller.
I m trying to pass parameters into a method so that
they can be altered and returned, can any one
suggest a way to do this.I think this is bad OO programing, it results in less readable code and may be hard to debug. Better is to make the method return the result and let the caller assign the new value. (This is my personal oppinion at least)