Deep cloning not working

[nitinram agarwal]

Hi,
I was doing some exercise as part of self learning to implement different sort algorithm and as an additional test, wanted to experiment with deep cloning as well. however the deep cloning is not working in the intended way. may be I am missing something obvious but am not able to get it and hence need some advice. here is the code

package dataStructureAlgorithm.bubbleSort;

import java.util.ArrayList;

//this class will sort the integer as an exercise
public class BubbleSort implements Cloneable {
	
	int element;
	static int counter=0;
	Integer[] intArray = new Integer[5];
	
	public void addElement(int element) {
		intArray[counter++] = element;
	}
	
	public Integer[] sortArrayUsingRecursion(Integer[] inputArray,int counter) {
		for(int i=0;i<counter;i++) {
			if (inputArray[i] > inputArray[i+1]) {
				int temp = inputArray[i+1];
				inputArray[i+1] =  inputArray[i];
				inputArray[i] = temp;
			}
		}
		if (counter == 1) {
			return inputArray;
		}
		
		return sortArrayUsingRecursion(inputArray,--counter);
		
	}
	
	public static void main(String[] args) {
		BubbleSort sortObj = new BubbleSort();
		int local = 4;
		sortObj.addElement(10);
		sortObj.addElement(15);
		sortObj.addElement(5);
		sortObj.addElement(91);
		sortObj.addElement(14);
		System.out.println(" before sorting the array is -" );
		sortObj.printArray(sortObj.intArray);
	
		System.out.println();
		sortObj.sortArrayUsingRecursion(sortObj.intArray,local);
		try {
			BubbleSort newSort = (BubbleSort) sortObj.clone();
			
			System.out.println(" after sorting the array is -" );
			sortObj.printArray(sortObj.intArray);
			
			System.out.println(" \n copied array");
			
			sortObj.printArray(newSort.intArray);
		} catch (CloneNotSupportedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	public BubbleSort clone() throws CloneNotSupportedException {
		BubbleSort newObj = new BubbleSort();
		newObj.intArray = this.intArray.clone();
		//for (int i=0;i<this.intArray.length;i++) 
			//newObj.intArray[i] = this.intArray[i];
		
		return newObj;
		
	}
	
	public void printArray(Integer [] array) {
		for(int i=0;i<=4;i++) {
			System.out.print(array[i] + ",");
			
		}
	}
}

and here is the output

before sorting the array is -
10,15,5,91,14,
after sorting the array is -
5,10,14,15,91,
copied array
5,10,14,15,91,

[Matthew Brown]

What were you expecting the result to be? You sort the array, then you take a copy. So the copy is going to match the sorted array. Are you sure you're doing things in the order you intended?

[Rob Spoor]

Also, your clone() method isn't written quite well. You shouldn't use new to create clones, or sub classes cannot override clone() well. I suggest you change it to this, also keeping the CloneNotSupportedException local to the clone() method:

public BubbleSort clone() {
    try {
        BubbleSort newObj = (BubbleSort)super.clone(); // Object.clone() returns an instance of the calling class
        newObj.intArray = this.intArray.clone();
        //for (int i=0;i<this.intArray.length;i++) 
            //newObj.intArray[i] = this.intArray[i];
        return newObj;
    } catch (CloneNotSupportedException e) {
        // BubbleSort implements Cloneable so this exception should not occur
        throw new AssertionError();
    }
}

[Campbell Ritchie]

And why are you using Integers rather than ints in an array called intArray?