使用Java从文本文件创建2D数组

Question

I just started learning java and now I'm trying to input a text file and make it a 2-dimensional string array. But somehow it shows no line found in the output(NoSuchElementException). So here is my code:

public class Maze {

final static int Max_Maze_Row = 20;
final static int Max_Maze_Column = 50;
public static String mazearray;

public static void create() throws Exception
{

   Scanner sc = new Scanner(new BufferedReader(new FileReader("Maze.txt")));
   String [][] mazearray = new String[Max_Maze_Row][Max_Maze_Column];
   while(sc.hasNextLine())
   {

       for(int i = 0 ;i<=Max_Maze_Row;i++)
       {
           for(int j = 0 ;j<=Max_Maze_Column;j++)
           {
               mazearray[i][j] = sc.nextLine();
               System.out.println(mazearray[i][j]);
           }
       }
   }
}

public static void display()
{
    System.out.println(Maze.mazearray); 
}

and here is the main method:

    public static void main(String[] args) throws Exception
{
    Maze mazeobject = new Maze();
    mazeobject.create();

}

So this is how the text file looks like: Maze.txt I've seen a lot of forum discussing the same questions, but none of them works for mine. Thanks in advance! I really appreciate your help.

Answer 1

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.Arrays;
import java.util.Scanner;

public class Maze {
    final static int Max_Maze_Row = 20;
    public String[] mazearray;

    public void create() throws Exception {

        Scanner sc = new Scanner(new BufferedReader(new FileReader("./Maze.txt")));
        mazearray = new String[Max_Maze_Row];
        int i = 0;
        while (sc.hasNextLine()) {
            mazearray[i++] = sc.nextLine();
        }
    }

    public void display() {
        System.out.println(Arrays.deepToString(mazearray));
    }

    public static void main(String[] args) throws Exception {
        Maze mazeobject = new Maze();
        mazeobject.create();
        mazeobject.display();
    }
}

You have to make sure there are enough lines in the ./Maze.txt as you required by Max_Maze_Row = 20 and Max_Maze_Column = 50 . Otherwise this line mazearray[i][j] = sc.nextLine(); will fail by java.util.NoSuchElementException: No line found

Answer 2

Change your create method like this:

public static void create() throws Exception {
    Scanner sc = new Scanner(new BufferedReader(new FileReader("Maze.txt")));
    String[][] mazearray = new String[Max_Maze_Row][Max_Maze_Column];
    int lineCounter = 0;

    while (sc.hasNextLine()) {
        String data = sc.nextLine();

        for (int i = 0; i < data.length(); i++) {
            mazearray[lineCounter][i] = String.valueOf(data.charAt(i));
            System.out.print(mazearray[lineCounter][i]);
        }

        System.out.println();
        lineCounter++;
    }
}