急！java，怎么把未知文件放进二维的array里？

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

public class PutArray {

public static void main(String[] args) {
int rowNum = 0;// 行数
int colNum = 0;// 列数
try {
String row = "";
Scanner sc = new Scanner(new File("d:\\test.txt"));
while (true) {
try {
row = sc.nextLine();
rowNum++;
} catch (NoSuchElementException e) {
colNum = row.length();
break;
}
}

char a[][] = new char[rowNum][colNum];//定义二维数组
Scanner sc1 = new Scanner(new File("d:\\test.txt"));
for (int i = 0; i < rowNum; i++) {
String content = sc1.nextLine();
for (int j = 0; j < colNum; j++) {
a[i][j] = content.charAt(j);
}
}

for (int i = 0; i < rowNum;