NumberFormatException 程序错误

Question

当我运行以下程序时，我得到了错误：

Exception in thread "main" java.lang.NumberFormatException: For input string: "[-52.06907251530153, -90.45811476077165]"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:492)
    at java.lang.Integer.parseInt(Integer.java:527)
    at code.readFile(code.java:31)
    at code.main(code.java:22)

这个错误是什么意思？为什么会这样？

import java.io.*;
import java.util.Arrays;

public class code
{
  public static void main (String [] args) throws IOException
  {

    int points = 10000, dimension = 2, lengthA = 100;//int variables are declared and initialized

    PrintWriter fileOut = new PrintWriter (new FileWriter ("arrayPoints.txt"));

    double length [] = new double [dimension];//array for length is declared
    double coordinate [][] = new double [points][dimension];//coordinate array is declared

    writeTofile(length, coordinate, points, dimension, lengthA);//calls writeTofile method

    for (int i = 0; i < points; i++){
      fileOut.println(Arrays.toString(coordinate[i]));//converts array to string and prints to file
                      }//end for
      fileOut.close();//writes to file
      readFile();// calls readFile method

  }//end main method
  public static void readFile() throws IOException
  {
    BufferedReader readFile = new BufferedReader (new FileReader ("arrayPoints.txt"));

    int readTimes [] = new int [10000];
    for(int i = 0; i < 10000; i++){
    readTimes [i] = Integer.parseInt(readFile.readLine());
    System.out.print(readTimes [i]);
    }//end for

  }

    public static void writeTofile (double length[], double coordinate[][], int points, int dimension, int lengthA)
    {
      for(int z = 0; z < dimension; z++){//fills the length array with the the set value of lengthA
      length[z] = lengthA;
      }//end for

    for(int x = 0; x < points; x++){//runs 1000 times to print 1000 data points
      for (int y = 0; y < dimension; y++){//runs 2 times to print an x and y coordinate
        coordinate [x][y]= (2 *Math.random() - 1) * length[y];// finds a random number in the range and assiigns it to the coordinate array
      }//end for
    }//end for
  }//writeTofile method
}//code

Answer 1

您正在从文件中读取一堆行，假设它们是整数并在它们上运行Integer.parseInt。它失败了，因为并非所有这些行都包含整数。

您可能希望尝试使用string.split() 和string.substring() 拆分每一行，然后再对这些非整数部分使用Double.parseDouble，而不是读取每一行并将其解析为整数。

Answer 2

因为[37.34351500606841, -30.837458930508465] 不是Integer。
它似乎发生在这里：Integer.parseInt(readFile.readLine());

Answer 3

在您发布的堆栈跟踪片段中，“37.34351500606841”不是整数。从不完整的堆栈跟踪中很难判断到底发生了什么，但是，如果您在该值上调用 Integer.parseInt，您将得到 NumberFormatException。