解析一个int时出现NumberFormatException [英] NumberFormatException while parsing an int

问题描述

所以我正在制作可以访问给定文件并从中保存/读取文件的文件读取器/写入器.从文件中读取文件时遇到了问题.内容是整数，字符串和由"|"分隔的双精度定界符.我正在使用StringTokenizer来分隔标记并将它们保存到每个单独的变量中，但是当我读取整数时，即使字符串仅包含一个整数，我也会得到NumberFormatException.

So I am making file reader/writer that can access a given file and save/read from it.I am having a problem while reading from the file. The contents are integers, string and double separated by "|" delimiters. I am using StringTokenizer to separate the tokens and save them to each individual variable but when I am reading the integers I get a NumberFormatException even though the string contains only an int.

这是代码:

FileReader fr = new FileReader(filename);
BufferedReader buff = new BufferedReader(fr);
String line;

while ((line = buff.readLine()) != null) {
    StringTokenizer st = new StringTokenizer(line, "|");
    while (st.hasMoreElements()) {
         int Id = Integer.parseInt(st.nextToken());
         String Name = st.nextToken();
         double cordX = Double.parseDouble(st.nextToken());
         double cordY = Double.parseDouble(st.nextToken());
    }
}

文件的示例行:

8502113|Aarau|47.391355|8.051251

错误:

java.lang.NumberFormatException: For input string: "8502113"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at storage.FileUtilities.readCitiesFromFile(FileUtilities.java:63)
at basics.Test.main(Test.java:16)

我在这里错过了什么吗? StringTokenizer是否以我不知道的某种方式篡改字符串?

Am I missing something here? Is StringTokenizer tampering the string in some kind of way that I don't know?

以下是创建文件的代码:

Here is the code that creates the file:

FileWriter fw = new FileWriter(filename, !overwrite); // For FileWriter true = append, false = overwrite, so we flip the value.
    BufferedWriter buff = new BufferedWriter(fw);
    String coordConvertor;

    for (int i = 0; i <= cities.size() - 1; i++) {
        buff.write(Integer.toString(cities.get(i).getId()));
        buff.write("|");
        buff.write(cities.get(i).getName());
        buff.write("|");
        coordConvertor = Double.toString(cities.get(i).getCoord().getX());
        buff.write(coordConvertor);
        buff.write("|");
        coordConvertor = Double.toString(cities.get(i).getCoord().getY());
        buff.write(coordConvertor);
        buff.newLine();

推荐答案

通过 st.nextToken()检索到的 String 中有隐藏的Unicode字符 . 请改用此代码删除它们

There are hidden unicode characters in the String your retrieved with st.nextToken(). Use this code instead to remove them

int Id = Integer.parseInt(st.nextToken().replaceAll("\\p{C}", ""));
String Name = st.nextToken().replaceAll("\\p{C}", "");
double cordX = Double.parseDouble(st.nextToken().replaceAll("\\p{C}", ""));
double cordY = Double.parseDouble(st.nextToken().replaceAll("\\p{C}", ""));

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