In this source code example, we will write a Java program to demonstrate how to implement the Insertion Sort algorithm in Java.

Insertion Sort Source Code in Java

public class InsertionSort {

   public void printArray(int[] arr) {
      int n = arr.length;
      for (int i = 0; i < n; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println();
   }

   public void sort(int[] arr) {
      int n = arr.length;

      for (int i = 1; i < n; i++) { // unsorted part
         int temp = arr[i];
         int j = i - 1; // sorted part

         while (j >= 0 && arr[j] > temp) {
            arr[j + 1] = arr[j]; // shifting larger elements to temp by 1 pos
            j = j - 1;
         }
         arr[j + 1] = temp;
      }
   }

   public static void main(String[] args) {
      int[] arr = new int[] { 5, 1, 2, 9, 10 };
      InsertionSort is = new InsertionSort();
      is.printArray(arr);
      is.sort(arr);
      is.printArray(arr);
   }
}

Output:

5 1 2 9 10 
1 2 5 9 10