Question

这应该将行数，单词和字符计入文件中。

但它不起作用。从输出中仅显示0。

代码：

public static void main(String[] args) throws IOException {
    int ch;
    boolean prev = true;        
    //counters
    int charsCount = 0;
    int wordsCount = 0;
    int linesCount = 0;

    Scanner in = null;
    File selectedFile = null;
    JFileChooser chooser = new JFileChooser();
    // choose file 
    if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
        selectedFile = chooser.getSelectedFile();
        in = new Scanner(selectedFile);         
    }

    // count the characters of the file till the end
    while(in.hasNext()) {
        ch = in.next().charAt(0);
        if (ch != ' ') ++charsCount;
        if (!prev && ch == ' ') ++wordsCount;
        // don't count if previous char is space
        if (ch == ' ') 
            prev = true;
        else 
            prev = false;

        if (ch == '\n') ++linesCount;
    }

    //display the count of characters, words, and lines
    charsCount -= linesCount * 2;
    wordsCount += linesCount;
    System.out.println("# of chars: " + charsCount);
    System.out.println("# of words: " + wordsCount);
    System.out.println("# of lines: " + linesCount);

    in.close();
}

我无法理解发生了什么。有什么建议吗？

Answer 1

您的代码只查看文件中默认令牌（单词）的第一个字符。

执行此操作ch = in.next().charAt(0)时，它会获取令牌（单词）的第一个字符，扫描程序会前进到下一个标记（跳过该标记的其余部分）。

Answer 2

不同的方法。使用字符串查找行，字和字符计数：

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

        Scanner in = null;
        File selectedFile = null;
        JFileChooser chooser = new JFileChooser();
        // choose file 
        if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
            selectedFile = chooser.getSelectedFile();
            in = new Scanner(selectedFile);
        }

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

        //display the count of characters, words, and lines
        System.out.println("# of chars: " + charsCount);
        System.out.println("# of words: " + wordsCount);
        System.out.println("# of lines: " + linesCount);

        in.close();
    }

<小时/> 注意：
对于其他编码样式，请使用new Scanner(new File(selectedFile), "###");代替new Scanner(selectedFile);。

###是需要的字符集。请参阅this和wiki

Answer 3

你在这里有几个问题。

首先是对行结束的测试会引起问题，因为它通常不是表示行尾的单个字符。有关此问题的详细信息，请阅读http://en.wikipedia.org/wiki/End-of-line。

单词之间的空白字符可能不仅仅是ASCII 32（空格）值。将制表符视为一种情况。您想要检查Character.isWhitespace（）的可能性超过。

您还可以使用How to check the end of line using Scanner?

中的两个扫描程序解决行尾问题

这是对您提供的代码以及输入和输出的快速破解。

import java.io.*;
import java.util.Scanner;
import javax.swing.JFileChooser;

public final class TextApp {

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

    Scanner fileScanner = null;
    File selectedFile = null;
    JFileChooser chooser = new JFileChooser();
    // choose file 
    if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
        selectedFile = chooser.getSelectedFile();
        fileScanner = new Scanner(selectedFile);         
    }

    while (fileScanner.hasNextLine()) {
      linesCount++;
      String line = fileScanner.nextLine();
      Scanner lineScanner = new Scanner(line);
      // count the characters of the file till the end
      while(lineScanner.hasNext()) {
        wordsCount++;
        String word = lineScanner.next();
        charsCount += word.length();
      } 

    lineScanner.close();
  }

  //display the count of characters, words, and lines
  System.out.println("# of chars: " + charsCount);
  System.out.println("# of words: " + wordsCount);
  System.out.println("# of lines: " + linesCount);

  fileScanner.close();
 }
}

这是测试文件输入：

$ cat ../test.txt 
test text goes here
and here

这是输出：

$ javac TextApp.java
$ java TextApp 
# of chars: 23
# of words: 6
# of lines: 2
$ wc test.txt 
 2  6 29 test.txt

字符数之间的差异是由于不计算空白字符，这些字符似乎是您在原始代码中尝试执行的操作。

我希望有所帮助。

Answer 4

您可以将每一行存储在List<String>，然后linesCount = list.size()。

计算charsCount：

for(final String line : lines)
    charsCount += line.length();

计算wordsCount：

for(final String line : lines)
    wordsCount += line.split(" +").length;

将这些计算结合在一起而不是单独进行这些计算可能是明智的想法。

Answer 5

使用Scanner方法：

int lines = 0;
int words = 0;
int chars = 0;
while(in.hasNextLine()) {
    lines++;
    Scanner lineScanner = new Scanner(in.nextLine());
    lineScanner.useDelimiter(" ");
    while(lineScanner.hasNext()) {
        words++;
        chars += lineScanner.next().length();
    }
}

Answer 6

看起来每个人都在建议你一个替代方案，

你的逻辑缺陷是，你没有遍历整行的所有字符。你只是循环遍历每一行的第一个字符。

 ch = in.next().charAt(0);

此外，charsCount -= linesCount * 2;中的2代表什么？

您可能还希望在访问文件时包含try-catch块。

  try {
            in = new Scanner(selectedFile);
        } catch (FileNotFoundException e) {}

Answer 7

也许我的代码会帮助你...一切正常

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;
import java.util.StringTokenizer;

public class LineWordChar {
    public static void main(String[] args) throws IOException {
        // Convert our text file to string
    String text = new Scanner( new File("way to your file"), "UTF-8" ).useDelimiter("\\A").next();
    BufferedReader bf=new BufferedReader(new FileReader("way to your file"));
    String lines="";
    int linesi=0;
    int words=0;
    int chars=0;
    String s="";
    // while next lines are present in file int linesi will add 1
        while ((lines=bf.readLine())!=null){
        linesi++;}
    // Tokenizer separate our big string "Text" to little string and count them
    StringTokenizer st=new StringTokenizer(text);
     while (st.hasMoreTokens()){
        `enter code here`  s = st.nextToken();
          words++;
    // We take every word during separation and count number of char in this words    
          for (int i = 0; i < s.length(); i++) {
              chars++;}
        }
     System.out.println("Number of lines: "+linesi);
     System.out.println("Number of words: "+words);
     System.out.print("Number of chars: "+chars);
 }
}

Answer 8

public class WordCount {

    /**
     * @return HashMap a map containing the Character count, Word count and
     *         Sentence count
     * @throws FileNotFoundException 
     *
     */
    public static void main() throws FileNotFoundException {
        lineNumber=2; // as u want
        File f = null;
        ArrayList<Integer> list=new ArrayList<Integer>();

        f = new File("file.txt");
        Scanner sc = new Scanner(f);
        int totalLines=0;
        int totalWords=0;
        int totalChars=0;
        int totalSentences=0;
        while(sc.hasNextLine())
        {
            totalLines++;
            if(totalLines==lineNumber){
                String line = sc.nextLine();
                totalChars += line.length();
                totalWords += new StringTokenizer(line, " ,").countTokens();  //line.split("\\s").length;
                totalSentences += line.split("\\.").length;
                break;
            }
            sc.nextLine();

        }

        list.add(totalChars);
        list.add(totalWords);
        list.add(totalSentences);
        System.out.println(lineNumber+";"+totalWords+";"+totalChars+";"+totalSentences);

    }
}

计算文件中的字符，单词和行

8 个答案: