Generate a Java program to implement Merge Sort algorithm to efficiently sort an array of elements in ascending order.

public class MergeSort {
 
    private int[] array;
    private int[] tempMergArr;
    private int length;
 
    public static void main(String a[]){
         
        int[] inputArr = {45,23,11,89,77,98,4,28,65,43};
        MergeSort mms = new MergeSort();
        mms.sort(inputArr);
        for(int i:inputArr){
            System.out.print(i);
            System.out.print(" ");
        }
    }
     
    public void sort(int inputArr[]) {
        this.array = inputArr;
        this.length = inputArr.length;
        this.tempMergArr = new int[length];
        doMergeSort(0, length - 1);
    }
 
    private void doMergeSort(int lowerIndex, int higherIndex) {
         
        if (lowerIndex < higherIndex) {
            int middle = lowerIndex + (higherIndex - lower