Count the Number of Occurrences of a Number in an Array

import java.io.*;
class ArrayClass {
  private static int noOfOccurrences(int[] a, int key, int currentIndex) {
    if (a.length == currentIndex) {
      return 0;
    }
    else if (a[currentIndex] == key) {
      return 1 + noOfOccurrences(a, key, currentIndex+1);
    }
    else {
      return noOfOccurrences(a, key, currentIndex+1);
    }
  }
  
  public static void main(String[] args) {
    System.out.print("{");
    
    int[] array = {2,3,4,1,7,8,3};
    for (int i = 0; i < array.length; i++) {
      System.out.print(array[i] + " ");
    }
    System.out.println("}");
    
    int key = 3;
    int output = noOfOccurrences(array, key, 0);
    System.out.println("Number of occurrences of " + key + ": "  + output);  
  }
}