Merge Sort algorithm in Java

MergeSortAlgo.java

import java.io.*;
import java.util.*;
 
 
public class MergeSortAlgo{
 
     static int arr[] = { 11,34,55,67,23,64,78,34,12,84,33,5,5};
     
     private void MergeSort(int [] arr)
     {
          System.out.println("Split array " + Arrays.toString(arr));
         if(arr.length > 1)
         {
             int [] leftpart; 
             int [] rightpart;
             int mid = arr.length / 2;
             if(arr.length%2 == 0)
             {
              leftpart = new int[mid];
              rightpart = new int[mid];
              System.arraycopy(arr, 0, leftpart, 0, mid);
              System.arraycopy(arr, mid, rightpart, 0, mid);
             }
             else
             {
              leftpart = new int[mid+1];
              rightpart = new int[mid];
              System.arraycopy(arr, 0, leftpart, 0, mid+1);
              System.arraycopy(arr, mid+1, rightpart, 0, mid);
             }
             
             
            
            
             
             MergeSort(leftpart);
             MergeSort(rightpart);
             int i=0,j=0,k=0;
             while ((i<leftpart.length) && (j<rightpart.length))
             {
                 if(leftpart[i] < rightpart[j])
                 {
                     arr[k] = leftpart[i];
                     i++;
                 }
                 else
                 {
                     arr[k] = rightpart[j];
                     j++;
                 }
                 k++;
             }
             
             while(i < leftpart.length)
             {
                 arr[k] = leftpart[i];
                 i++;
                 k++;
             }
             
             while(j < rightpart.length)
             {
                 arr[k] = rightpart[j];
                 j++;
                 k++;
             }
            
         }
         System.out.println("Mergerd array " + Arrays.toString(arr)); 
     }
     
     public static void main(String []args)
     {
        System.out.println("Unsorted array " + Arrays.toString(arr));
        MergeSortAlgo obj = new MergeSortAlgo();
        obj.MergeSort(arr);
        System.out.println("Sorted array "  + Arrays.toString(arr));
     }
 
}