java - 当文件有多个空格时如何计算文件中的单词数？ - java

Question

我试图在 linux 中实现命令“wc 文件名”的功能。此命令计算以下数量:

• 行
• 单词
• 字节数

在文件中。

这是我的代码:

public class wc {
    public static void main(String[] args) throws IOException {
    //counters
    int charsCount = 0;
    int wordsCount = 0;
    int linesCount = 0;

    Scanner in = null;

    try(Scanner scanner = new Scanner(new BufferedReader(new FileReader(new File("Sample.txt"))))){
        File file = new File("Sample.txt");

        while (scanner.hasNextLine()) {

            String tmpStr = scanner.nextLine();
            if (!tmpStr.equalsIgnoreCase("")) {
                String replaceAll = tmpStr.replaceAll("\\s+", "");
                charsCount += replaceAll.length();
                wordsCount += tmpStr.split(" ").length;
            }
            ++linesCount;
        }

    System.out.println("# of chars: " + charsCount);
    System.out.println("# of words: " + wordsCount);
    System.out.println("# of lines: " + linesCount);
    System.out.println("# of bytes: " + file.length());

    }
  }
}

问题是在文件中有这样的文本:

Hex Description                 Hex Description

20  SPACE
21  EXCLAMATION MARK            A1  INVERTED EXCLAMATION MARK
22  QUOTATION MARK              A2  CENT SIGN
23  NUMBER SIGN                 A3  POUND SIGN

有多个不同长度的空间。有时翻倍，有时甚至更多。如何重构我的代码以便能够正确计算字数？如何去掉多个空格？

Answer 1

String#split接受一个正则表达式，所以你可以简单地拆分 \\s+ (多个空格):

public static void main (String[] args) {
    String input = "Some input  with     more     than   one   space";
    String[] words = input.split("\\s+");
    System.out.println(words.length + " words");
}

输出:

7 words

参见 on ideone.com .