尝试通过读取文件打印二维数组时，我在输出中收到 Null

Question

Im trying to read a file from "contacts" and putting it in a 2d array called sData. Im trying to print the content on the console window but however i am receving null on my output. Am i trying to print the content in an incorrect way or some? The code was delivered to us however it seems to fail on me any help?

Joe - 1111245678
Tom - 3431234567
Lom - 7771234568
King - 76681234567
Dom - 6842234567

 import java.io.*;
import java.util.Scanner;

public class phonenumbers {


    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub
        File f= new File ("Contacts.txt");
        ReadData(f);






    }
    public static void printArr (String [][] hex) throws Exception{

        for (int row = 0; row < hex.length; row++) {

              for (int column = 0; column < hex[row].length; column++) {

                System.out.print(hex[row][column] + " ");

              }


              System.out.println();

            }
    }

    public static int CountLines(File f) throws Exception {
        int lines = 0;
        Scanner reader = new Scanner (f);

        while (reader.hasNextLine()) {
            String s = reader.nextLine();
            s = s.trim();
            if (s.length() == 0) {
                break;
            }
            lines++;

        }
        reader.close(); 
        return lines;       
    }


    public static String [][] ReadData(File f) throws Exception {
        Scanner reader = new Scanner (f);
        int numLines = CountLines(f);
        String [][] sData = new String [numLines] [];

        for (int line = 0; line <numLines; line++ ) {
            String l = reader.nextLine(); 
            l = l.trim();
            String [] temp = l.split(" ");
            sData [line] = new String [temp.length];
        }
        printArr(sData);
        reader.close();
        return sData;


    }


}

Output
null null null 
null null null
null null null
null null null
null null null

Answer 1

replace

sData [line] = new String [temp.length];

with

sData [line] = temp;

you currently are just putting a empty array the size of the intended array.