My solution is:

int max = -100; for (int x=0;x<4;x++){ for (int y=0;y<4;y++){ int sum = 0; sum += arr.get(x).get(y); sum += arr.get(x).get(y+1); sum += arr.get(x).get(y+2); sum += arr.get(x+1).get(y+1); sum += arr.get(x+2).get(y); sum += arr.get(x+2).get(y+1); sum += arr.get(x+2).get(y+2); if (sum > max) max = sum;
} } System.out.println(max);

this my code:

import java.io.; import java.math.; import java.security.; import java.text.; import java.util.; import java.util.concurrent.; import java.util.function.; import java.util.regex.; import java.util.stream.*; import static java.util.stream.Collectors.joining; import static java.util.stream.Collectors.toList;

public class solution{ public static void main(String[] args){ Scanner scan = new Scanner(System.in); int [][]a = new int[6][6]; for(int i = 0; i<6; i++){ for(int j =0; j<6; j++){ a[i][j] = scan.nextInt(); } }

    System.out.println(findlarges(a));
}

public static int findlarges(int [][]a){
    int largest = Integer.MIN_VALUE;

    for(int i = 1; i<=4; i++){
        for(int j = 1; j <=4; j++){
            int sum = 0;
            sum += a[i][j] + a[i+1][j-1] + a[i+1][j] + a[i+1][j+1]
            + a[i-1][j-1] + a[i-1][j] + a[i-1][j+1];
            if(sum > largest){
                largest = sum;
            }
        }
    }
    return largest;
}

}

Java 2D Array

public class Solution { public static void main(String[] args) throws IOException { Scanner s= new Scanner(System.in); int[][] arr=new int[6][6]; for (int i = 0; i < 6; i++) { for (int j = 0; j < 6; j++) { arr[i][j]=s.nextInt(); } } System.out.println(largestHourGlass(arr)); } public static int largestHourGlass(int[][] arr){ int largestHourGlass=Integer.MIN_VALUE; for (int i = 1; i <= 4; i++) { for (int j = 1; j <= 4; j++) {

            int sum = arr[i][j]+arr[i+1][j+1]+arr[i-1][j-1]+ arr[i+1][j-1]+arr[i-1][j+1]+arr[i-1][j]+arr[i+1][j];
            if(sum>largestHourGlass){
                largestHourGlass=sum;
            }
        }
    }
    return largestHourGlass;
}
    //Reduced Complexity and less calculations

}

import java.util.; import java.util.Arrays; public class Solution { public static void main(String[] args) { Scanner sc=new Scanner(System.in); int arr[][]= new int [6][6]; for(int i=0;i<6;i++) { for(int j=0;j<6;j++) { arr[i][j]=sc.nextInt(); } } * int sum=0; int n=0; int k[]= new int[16]; for(int i=0;i<=3;i++) { for(int j=0;j<=3;j++) { sum=arr[i][j]+arr[i][j+1]+arr[i][j+2]+arr[i+1][j+1] +arr[i+2][j]+arr[i+2][j+1]+arr[i+2][j+2]; k[n]=sum; n++;
} } Arrays.sort(k); System.out.println(k[15]); sc.close(); } }