Valid Sudoku

https://leetcode.com/problems/valid-sudoku/

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

A partially filled sudoku which is valid.

Note:
A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

public class Solution {
    public static boolean isValidSudoku(char[][] board) {
        boolean[][]row=new boolean[9][10];
        boolean[][]col=new boolean[9][10];
        boolean[][]box=new boolean[9][10];
        for(int i=0;i<9;i++){
            for(int j=0;j<9;j++){
            if(board[i][j]=='.') continue;
            int x=board[i][j]-'0';
            int boxnum=0;
            if(i<3&&j<3) boxnum=0;
            else if(i<3&&j>=3&&j<6) boxnum=1;
            else if(i<3&&j>=6&&j<9) boxnum=2;
            else if(i>=3&&i<6&&j<3) boxnum=3;
            else if(i>=3&&i<6&&j>=3&&j<6) boxnum=4;
            else if(i>=3&&i<6&&j>=6) boxnum=5;
            else if(i>=6&&j<3) boxnum=6;
            else if(i>=6&&j>=3&&j<6) boxnum=7;
            else if(i>=6&&j>=6) boxnum=8;
             if(row[i][x]==true||col[j][x]==true||box[boxnum][x]==true){
                 return false;
             }
             row[i][x]=true;col[j][x]=true;box[boxnum][x]=true;
            }
        }
        return true;
    }
    public static void main(String[]args){
    String[]t={".87654321","2........","3........","4........","5........","6........","7........","8........","9........"};
    char[][]board=new char[9][9];
    for(int i=0;i<9;i++){
        board[i]=t[i].toCharArray();
        System.out.println(board[i]);
    }
    System.out.println(isValidSudoku(board));
    }
}