未知 "NumberFormatting" 问题

Question

（提前，抱歉冗长且有点小众 post 但我被卡住了）完成 Java 编程新手在这里，我一直在关注 "Java ALL-IN-ONE for Dummies" 书，我遇到了一个似乎无法克服的障碍。出于某种原因，我的代码以及从本书下载网站获取的代码抛出了 NumberFormatException。我的代码如下..

`package videoRead;

import java.io.*;
import java.text.NumberFormat;

public class reader 
{

    public static void main(String[] args)
    {
        NumberFormat cf = NumberFormat.getCurrencyInstance();
        BufferedReader in = getReader("Movie.txt");
        Movie movie = readMovie(in);
        while (movie != null)
        {
        String msg = Integer.toString(movie.year);
        msg += ": " + movie.title;
        msg += " (" + cf.format(movie.price) + ")";
        System.out.print(msg);
        movie = readMovie(in);
        }

    }
    private static BufferedReader getReader(String name)
    {
        BufferedReader in = null;
        try
        {
            File file = new File(name);
            in = new BufferedReader(
                new FileReader("C:\Users\hunte\Desktop\Movie.txt") );
        }
        catch (FileNotFoundException e)
        {
            System.out.print(
                    "the file doesn't exist.");
            System.exit(0);
        }
        return in;
    }

    private static Movie readMovie(BufferedReader in)
    {
        String title;
        int year;
        double price;
        String line = "";
        String[] data;

        try
        {
            line = in.readLine();
        }
        catch (IOException e)
        {
            System.out.print("I/O Error");
            System.exit(0);
        }
        if (line == null)
                return null;
        else
        {
            data = line.split("\t");
            title = data[0];
            year = Integer.parseInt(data[1]);
            price = Double.parseDouble(data[2]);
            return new Movie(title, year, price);
        }
    }

    private static class Movie 
    {
        public String title;
        public int year;
        public double price;
        public Movie(String title, int year, double price)
        {
        this.title = title;
        this.year = year;
        this.price = price;
        }
    }

}

错误代码为

`1946: It's a Wonderful Life (.95)1972: Young Frankenstein (.95)1973: Star Wars (.95)1987: The Princess Bride (.95)1989: Glory (.95)Exception in thread "main" java.lang.NumberFormatException: For input string: "14.95"
        at java.base/java.lang.NumberFormatException.forInputString(Unknown Source)
        at java.base/java.lang.Integer.parseInt(Unknown Source)
        at java.base/java.lang.Integer.parseInt(Unknown Source)
        at videoRead/videoRead.reader.readMovie(reader.java:65)
        at videoRead/videoRead.reader.main(reader.java:20)`

我的问题是为什么会这样，我该如何解决？或者我该如何捕捉不会破坏代码的异常？

（此外，如果有人能告诉我为什么我的代码不会拆分行，那也很棒）

谢谢！！

Answer 1

根据错误消息，这是文本文件中的字符串格式，因此下面的代码根据 space 分隔符拆分行，并通过删除所有额外字符

来过滤值

注意：如果文本文件中的每条记录都是采用这种格式的单独一行，则此代码有效

String s ="1946: It's a Wonderful Life (.95)";
String[] ar = s.split(" ");
System.out.println(ar[0].substring(0, ar[0].length()-1));
String str = String.join("," ,Arrays.copyOfRange(ar, 1, ar.length-2)).replaceAll(",", " ");
System.out.println(str);
System.out.println(ar[ar.length-1].substring(2, ar[ar.length-1].length()-1));

输出：

1946
It's a Wonderful
14.95

Answer 2

price = Double.parseDouble(data[2]);

给您一个错误，因为您 Movie.txt 文件中的价格值包含一个 $ 符号。从文件中删除 $ 或在您的代码中替换它，如下面的代码所示

String p = data[2].toString().replace("$","");
price = Double.parseDouble(p);

Answer 3

实际发生的错误，来自：

 year = Integer.parseInt(data[1]);

不是：

 price = Double.parseDouble(data[2]);

如：

For input string: "14.95"

at java.base/java.lang.Integer.parseInt(Unknown Source)

错误告诉您：您尝试将 14.95 解析为 int 值。整数值没有浮点数。

所以问题是：您正在尝试将浮点数解析为 int。

根本原因：你的拆分是错误的，你是putting/parsing错误的拆分数据。

deadpool 的精彩回答中解释了如何修复输入数据的错误解析。

未知 "NumberFormatting" 问题

unknown "NumberFormatting" Issue

java

string

exception-handling

number-formatting