Program to Check for symmetric matrix

/* Program to Check for symmetric matrix*/

import java.io.DataInputStream;   // to load DataInputStream class          

class P4
{
    public static void main(String args[ ])
    {
        int i, j, flag = 0;
        int matrix[][]= new int[3][3];
        DataInputStream in = new DataInputStream(System.in);

        try
        {
            System.out.println(" Input 3 * 3 matrix  elements : ");
            for (i=0;i<3;i++)
            for(j=0;j<3;j++)
                      matrix[i][j]= Integer.parseInt(in.readLine());
        }
        catch(Exception e) {  System.out.println("I/O Error");   }

        System.out.println(" Matrix is : ");
        for (i=0;i<3;i++)
        {
             for(j=0;j<3;j++)
            System.out.print(" "+matrix[i][j]+" ");
             System.out.println();
        }

        for (i=0;i<3;i++)
            for(j=0;j<3;j++)
                  if (matrix[i][j] != matrix[j][i])
                        flag = 1;

        if (flag == 1)
                 System.out.println(" Matrix is not symmetric");
        else
                  System.out.println(" Matrix is symmetric");
    }
}