Java-按字符的Char文本文件读入2D数组

Question

I'm attempting to return the array "seats" which is essentially supposed to return data from a text file - 15x30 grid of "#". I've tried a multitude of things, but I'm getting frustrated as I have VERY little experience with java. My code compiles but it doesn't print correctly when calling the method.

If anyone can help fix either the constructor or the method I would greatly appreciate it...and if there's any way you could refrain from using code that is terribly complicated I would appreciate it as well. And explain! Thank you!

import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.util.*;

public class TicketManager
{
    private static int NUMROWS = 15;
    private static int NUMCOLS = 30;
    private char[][] seats = new char[NUMROWS][NUMCOLS];
    private double[] price = new double[NUMROWS];
    private int seatsSold;
    private int totalRevenue;

    public TicketManager()
    {
        try
        {
            BufferedReader br = new BufferedReader(new FileReader("seatAvailability.txt"));
            String line = br.readLine();    

            while (line != null)
            {
               for (int i = 0; i < 15; i++)
               {
                   seats[i] = line.toCharArray();
               }
            }
        }
        catch(IOException exception)
        {
            System.out.println("Error processing file: " + exception);
        }
    }

    public String returnSeats()
    {
        String result = "";
        for (int i =0; i <seats.length; i++)
        {
            for (int j = 0; j < seats.length; j++)
            {
                result += seats[i][j] + " ";
            }
            System.out.println("");
        }
        return result;
    }
}

Answer 1

Slight problem in your loop. Updated section of code below:

 public TicketManager(){
   try{
    BufferedReader br = new BufferedReader(new FileReader("seatAvailability.txt"));
       for (int i = 0; i < 15; i++)
        String line = br.readLine();    
         seats[i] = line.toCharArray();
       }
   }catch(IOException exception){
       System.out.println("Error processing file: " + exception);
   }
 }

It will read 15 rows(lines) for input. Make sure you enter exact 30 characters in your each line. Also don't use spacing in input line characters eg your input for each line should be like X0000xx00xx0xx0xx000xx0xxx0x00

In your returnSeats method, use seats[0].length or seats[i].length in the inner loop and StringBuilder as:

public String returnSeats(){
    StringBuilder result = new StringBuilder();
    for (int i =0; i <seats.length; i++){
        for (int j = 0; j < seats[i].length; j++){
            //append seat character in the result string
            result.append(seats[i][j]);
        }
        //append new line character in the string in between
        result.append(System.lineSeparator());
    }
    return result.toString();
}

Answer 2

Where you have for (int j = 0; j < seats.length; j++) , you need to have for (int j = 0; j < seats[i].length; j++) .

This has to do with how multi-dimensional arrays work. They are arrays of arrays. So when you write seats.length , you are asking how many rows there are. Calling seats[i].length asks how many members are in row i .