将整数从文件存储到2D数组

Question

I am trying to import similar to this

5 5
1 1
3 3
1 1 1 1 1
1 0 1 0 1
1 0 1 0 1
1 0 0 0 1
1 1 1 1 1

files into 2D array but I am having hard time, this is my code so far, which does nothing, there aren't syntactic mistakes, so I don't get any errors but a blank console and I don't know what I did wrong. The size of the array is the first 2 numbers inside the file.

package main;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class oboroten {
public static void main(String[] args) {
    int x, y;
    x = y = 0;
    int[][] maze = new int[x][y];
    try {
        Scanner reader = new Scanner(new File("C:\\Users\\User\\Desktop\\mazes\\input.txt"));
        x = reader.nextInt();
        y = reader.nextInt();
        for (int i = 0; i < x; i++){
            for (int j = 0; j < y; j++){
                maze[i][j] = reader.nextInt();
                System.out.println(maze[i][j]);
            }
        }       
        reader.close();
    } catch (FileNotFoundException e1) {
        System.out.println("Problem with the file");
        e1.printStackTrace();
    }
}}

Answer 1

You initial you array with the size 0. So nothing will be addet there.

You have to initial the array after you read the file and get the dimensions. Try this:

public static void main(String[] args) {
    int x, y;
    int[][] maze;
    try {
        Scanner reader = new Scanner(new File("C:\\Users\\User\\Desktop\\mazes\\input.txt"));
        x=reader.nextInt();
        y=reader.nextInt();
        maze = new int[x][y];
        for (int i=0; i<x; i++){
            for (int j=0; j<y; j++){
                maze[i][j]=reader.nextInt();
                System.out.println(maze[i][j]);
            }
        }       
        reader.close();
    } catch (FileNotFoundException e1) {
        System.out.println("Problem with the file");
        e1.printStackTrace();
    }
}