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String.length()的奇怪行为

[英]Strange behaviour of String.length()

I have class with main: 我有主课:

public class Main {

// args[0] - is path to file with first and last words
// args[1] - is path to file with dictionary 
public static void main(String[] args) {
    try {
        List<String> firstLastWords = FileParser.getWords(args[0]);
            System.out.println(firstLastWords);
        System.out.println(firstLastWords.get(0).length());

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

and I have FileParser: 我有FileParser:

public class FileParser {

    public FileParser() {
    }

    final static Charset ENCODING = StandardCharsets.UTF_8;


    public static List<String> getWords(String filePath) throws IOException {
        List<String> list = new ArrayList<String>();
        Path path = Paths.get(filePath);

        try (BufferedReader reader = Files.newBufferedReader(path, ENCODING)) {
            String line = null;
            while ((line = reader.readLine()) != null) {

                String line1 = line.replaceAll("\\s+","");
                if (!line1.equals("") && !line1.equals(" ") ){
                    list.add(line1);
                }
            }
            reader.close();
        }
        return list;
    }   
}

args[0] is the path to txt file with just 2 words. args[0]是只有2个单词的txt文件的路径。 So if file contains: 所以,如果文件包含:

тор
кит

programm returns: 程序返回:

[тор, кит]
4

If file contains: 如果文件包含:

т
тор
кит

programm returns: 程序返回:

[т, тор, кит]
2


even if file contains: 即使文件包含:
//jump to next line //跳到下一行
тор тор
кит кит

programm returns: 程序返回:

[, тор, кит]
1

where digit - is length of the first string in the list. 其中digit - 是列表中第一个字符串的长度。

So the question is why it counts one more symbol? 所以问题是为什么它又算一个符号呢?

Thanks all. 谢谢大家。

This symbol as said @Bill is BOM ( http://en.wikipedia.org/wiki/Byte_order_mark ) and reside at the beginning of a text file. 这个符号表示@Bill是BOM( http://en.wikipedia.org/wiki/Byte_order_mark )并且位于文本文件的开头。 So i found this symbol by this line: 所以我通过这一行找到了这个符号:

System.out.println(((int)firstLastWords.get(0).charAt(0)));

it gave me 65279 它给了我65279

then i just changed this line: 然后我改变了这一行:
String line1 = line.replaceAll("\\\\s+",""); to this 对此

String line1 = line.replaceAll("\uFEFF","");

Cyrillic characters are difficult to capture using Regex, eg \\p{Graph} does not work, although they are clearly visible characters. 使用正则表达式很难捕获西里尔字符,例如\\p{Graph}不起作用,尽管它们是清晰可见的字符。 Anyways, that is besides the OP question. 无论如何,这是OP问题之外的问题。

The actual problem is likely due to other non-visible characters, likely control characters present. 实际问题可能是由于其他不可见的字符,可能存在控制字符。 Try following regex to remove more: replaceAll("(\\\\s|\\\\p{Cntrl})+","") . 尝试使用以下正则表达式删除更多: replaceAll("(\\\\s|\\\\p{Cntrl})+","") You can play around with the Regex to further extend that to other cases. 您可以使用正则表达式进一步扩展到其他情况。

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