如何创建多维数组以从.txt文件中获取输入

Question

我正在尝试创建一个大小为[3]和[100]的2d数组，其想法是它将存储三个字符串，这些字符串将存储在一个用tab分隔的文本文件中。我已经在网上搜索了任何帮助，但没有找到任何好的答案。它需要是一个通过Java存储的数组。

应该是这样的：

• 将字符串文件与filename.txt关联
• 创建一个大小为3列和100行的2d数组。在这里，它应该从左到右存储数据，每行有3个字符串，然后分离到新行
• 那么我需要一种方法将文本文件中的字符串添加到数组中。最后它应该打印数组的内容

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.*;
public class ArrayDirectory {
    public static void main(String args[]) {
        String file = ("directory.txt");
        // initialises the file linked to the String file
        String[][] Entry = new String[3][50];
        // creates a 2d array with 3 columns and 50 rows.
        readFromFile.openTextFile(file);
        //should read from file
        String line = readFromFile.readLine();
        int count = 0;
        while (line != null) {
            input[count] = String.split("");
            Entry = readFromFile.readline();
        }
        for (int h = 0; h < input.length; h++) {
            System.out.println(input[h]);
        }
    }
}

Answer 1

几点：

• 你没有办法阅读这份文件
• 当您的注释与之相反时，您的数组有3行50列
• 你试图在一个空格上拆分，而不是在一个选项卡上拆分

请参阅代码中解释其作用的注释：

public class ArrayDirectory {
public static void main(String args[]) throws FileNotFoundException {
    String file = ("lab4b2.txt");
    Scanner scan = new Scanner(new FileReader(file));
    // initialises the scanner to read the file file
    String[][] entries = new String[100][3];
    // creates a 2d array with 100 rows and 3 columns.
    int i = 0;
    while(scan.hasNextLine()){
        entries[i] = scan.nextLine().split("t");
        i++;
    }
    //loops through the file and splits on a tab
    for (int row = 0; row < entries.length; row++) {
        for (int col = 0; col < entries[0].length; col++) {
            if(entries[row][col] != null){
                System.out.print(entries[row][col] + " " );
            }
        }
        if(entries[row][0] != null){
            System.out.print("n");
        }
    }
    //prints the contents of the array that are not "null"
}
}

Answer 2

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ArrayDirectory{
        public static void main(String args[]) throws IOException {
            BufferedReader readFromFile = new BufferedReader(new FileReader("test.txt"));

            int count = 0;
            String[][] entry = new String[100][3];
            String line = readFromFile.readLine();

            while (line != null) {
                //I don't know the layout of your file, but i guess it is: "XX YY ZZ", with spaces inbetween.
                String[] temp = line.split(" "); //temp here will be: [XX][YY][ZZ]
                for (int i = 0; i < temp.length; i++) {
                    entry[count][i] = temp[i];
                }
                line = readFromFile.readLine();
                count++;

            }
            readFromFile.close();
            for (int j = 0; j < entry.length; j++) {
                for (int k = 0; k < entry[0].length; k++) {
                    System.out.print(entry[j][k] + " ");
                }
                System.out.println();
            }
        }
}

在此处阅读有关字符串拆分的信息：http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#split(java.lang.String(

此外，变量应该总是以小写字母开头，只有类的第一个字母应该是大的。