Java Lang 数字格式异常问题

Question

我正在尝试将文本文件中的文本存储为 Java 程序中的变量。

源码如下:

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

/**
 * Write a description of class Reader here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Reader
{
    // instance variables - replace the example below with your own
    private int areaNumber;
    private int studyPeriod;
    private int rentalCharges;
    private int CAPEX;
    private int OPEX;
    private double interestRate;

    private int[] rolloutPlanPerArea;
    private int householdsPerArea;
    private double adoptionRatePerArea;

    private String fileName = "practical6a.txt";

    public void run(){
        load(fileName);
    }

    private void load(String fileName){
        try {
            BufferedReader reader = new BufferedReader(new FileReader(fileName));

            String currentLine = null;

            while ((currentLine = reader.readLine()) != null) {
                areaNumber = Integer.parseInt(currentLine.trim());
                studyPeriod = Integer.parseInt(currentLine.trim());
                rentalCharges = Integer.parseInt(currentLine.trim());
                CAPEX = Integer.parseInt(currentLine.trim());
                OPEX = Integer.parseInt(currentLine.trim());
                interestRate = Integer.parseInt(currentLine.trim());
            }

            reader.close();

            System.out.print(areaNumber);

        } 
        catch (IOException e) {
            e.printStackTrace();
        } 
    }
    }

每次代码运行时，我都会收到字符串“”的 NumberFormatError，就好像程序试图读取的行中没有任何内容一样。

文本文件包含不同行的值。 EG

7
3
2
1

因为每一行都有一些东西，我质疑为什么没有设置变量？

Answer 1

NumberFormatError for String ""

您的文件必须以新的空行结束。要么删除它，要么在 Integer.parseInt 调用之前检查 !currentLine.trim().equals("")。