Question

我试图练习一些java而且我很困惑。我试图将多个数字输入一个3 * 3数组，但是当我运行我的程序时，我得到一个compliation错误（线程“main”java.lang.NumberFormatException中的异常）？如何从Joptionpane解析多个int到数组？

public static int[][] enterMatrix() {
    String NumberstoParse = JOptionPane.showInputDialog("Enter list: ");
    int UserInput = Integer.parseInt(NumberstoParse);
    int[][] matrix = new int[3][3];

    for (int i = 0; i < matrix.length; i++)
        for (int j = 0; j < matrix[i].length; j++)
            matrix[i][j] = UserInput;

    return matrix;
}

}

Answer 1

我认为主要问题是从JOptionPane解析String时。 Integer.parseInt（）查看逗号并抛出NumberFormatException。可能值得对这个方法进行一些测试，可能还有JShell！

这里，我已经输入了字符串“1,2,3,4,5,6,7,8,9”并使用了从类String中拆分的方法来生成一个由（“，” \ S +“）。这意味着，围绕匹配的正则表达式进行拆分，这里是“逗号和一个或多个空白字符”。然后使用Integer.parseInt（）处理数组中的每个字符串。

public static int[][] enterMatrix() {
    String numberstoParse = JOptionPane.showInputDialog("Enter list: ");

    String[] splitNumbers = numberstoParse.split(",\\s+");

    int[][] matrix = new int[3][3];
    int ctr = 0;
    for (int i = 0; i < matrix.length; i++)
        for (int j = 0; j < matrix[i].length; j++) {
            matrix[i][j] = Integer.parseInt(splitNumbers[ctr]);
            ctr++;
        }
        return matrix;
}

Answer 2

添加到Alex已经添加的内容是代码，它将处理一些边界线问题，有些测试用例包括一些测试用例。代码记录在案，我希望这有帮助...

public class Dummy
{
    public static void main(String[] args)
    {
        String temp = "";
        for(int x = 0; x <10; x++){
           temp = temp + x+"";
           int[][] matrix = enterData(temp);
           System.out.println("Given Input:" + temp);
           if(matrix != null){
               for (int i = 0; i < matrix.length; i++){
                   for (int j = 0; j < matrix[i].length; j++)
                       System.out.print(matrix[i][j] + " ");
                   System.out.println();
               }
           }
           System.out.println("-------------");
           temp +=",";
        }

    }

    //Once you understand the test cases, you can remove the argument and use the JOptionPane for input
    public static int[][] enterData(String input)
    {
        //TODO: Please user JOPtionPane I have added this just to make the test cases work
        //String input = JOptionPane.showInputDialog("Enter list: ");
        //This will split the Input on the basis of ","
        String[] inputArr = input.split(",");

        //Variable has a counter which which will represent the number of inputs received
        int inputArrCount = 0;
        int[][] matrix = new int[3][3];


        //If the size is greater than 9, then as u suggested an error is printed
        if(inputArr.length > 9 ){
            System.err.println("Number length > 9");
            return null;
        }


        for(int i = 0; i <matrix.length; i++){
            for (int j = 0; j < matrix[i].length; j++){
                //If to just track that inputArrCount never goes beyond the inputArr elements
                if(inputArrCount < inputArr.length){
                    int temp = Integer.parseInt(inputArr[inputArrCount++]);
                    matrix[i][j] = temp;
                }

            }                
        }

        return matrix;
    }

}

从Joptionpane解析多个整数

2 个答案: