java - 读入数组并显示数组

Question

我是java新手，我在这方面遇到了麻烦。我需要制作2个不同的程序。一个用于制作txt文件，另一个用于执行。第一个程序制作网格。第二个在方法中读取 txt，然后我应该在 main 中调用它。我似乎无法弄清楚。

初始数组(txt.file):

import java.util.ArrayList;
import java.util.Scanner;
import java.util.Random;
import java.util.Collections;

public class Grid {
    public static void main(String[] args) {
        ArrayList<Integer> indNum = new ArrayList<Integer>();
        ArrayList<Integer> elemNum = (ArrayList<Integer>) indNum.clone();
        ranNum(indNum);
        ranNum(elemNum);

        String grid[][] = mGrid();
        replaceGrid(grid, indNum.get(0), elemNum.get(0));
        replaceGrid(grid, indNum.get(1), elemNum.get(1));
        replaceGrid(grid, indNum.get(2), elemNum.get(2));
        disGrid(grid);
    }

    public static String[][] mGrid() {
        String[][] Array = { { " *", " *", " *", " *", " *" },
                             { " *", " *", " *", " *", " *" },
                             { " *", " *", " *", " *", " *" },
                             { " *", " *", " *", " *", " *" },
                             { " *", " *", " *", " *", " *" }       
                           };
        return Array;
    }

    public static void disGrid(String[][] array) {
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                System.out.print(array[i][j]);
            }
            System.out.println();
        }
    }

    public static ArrayList<Integer> ranNum(ArrayList<Integer> ran) {
        for (int i = 0; i < 5; i++) {
            ran.add((i));
        }
        Collections.shuffle(ran);
        ran.remove(4);
        ran.remove(3);
        return ran;
    }

    public static String[][] replaceGrid(String[][] array, int num1, int num2) {
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                array[num1][num2] = " O";
            }
        }
        return array;
    }
}

输出:

 O * * * *
 * * * * *
 * * * * *
 * * O * *
  * * * O *

三个 O 随机放置在网格中第二部分 通过执行数组读入并显示:

package Execute;

import java.util.ArrayList;
import java.util.Scanner;
import java.util.Random;
import java.util.Collections;
import java.io.*;

  public class part2 {
    public static void main(String[] args) {
        ArrayList<String> makeGrid= new ArrayList<String>();
         readFile(makeGrid);            
        System.out.print(makeGrid); 
    }

    public static void readFile(ArrayList<String> exec) {
        try {
            Scanner reader = new Scanner(new File("Grid.txt"));
            do {
                exec.add(reader.nextLine());
            }while (reader.hasNext());
        } catch (FileNotFoundException fnf) {
            System.out.println("File was not found");
        }
    }   
}

当我运行它时，它不会存储旧网格并显示它。相反，它只是打印出我在一行中编写的整个代码。我如何执行代码并将其存储在数组列表中以便我可以操作它？

Answer 1

首先，您需要 while (reader.hasNextLine())

如果您希望数组列表显示为多行，您可以手动添加换行符

exec.add(reader.nextLine() + "\n");

或者您实际上可以打印每一行，而不仅仅是数组列表

readFile(makeGrid);
for (String line : makeGrid) {
    System.out.println(line);
}

顺便说一句，不建议将可变集合作为参数传递到方法中。你应该return来自 readFile() 的新数组列表