Question

我必须计算文本文件中的字符数。我想用for循环来做，但是，我不知道如何引用文件的长度？

public void countLetters(String) {
    for (int i = 0; i <      ; i++) {

    }
}

我应该在i <之后写些什么？

Answer 1

您首先需要阅读该文件的内容。你可以用以下方式完成。

FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);

其中file是文件对象，即在您的情况下，您要读取的文本文件。然后读取文件的每一行，如下

String temp;
int totalNoOfCharacters = 0;
int noOfLines = 0;  //To count no of lines IF you need it
while ( (temp = br.readline()) != null ){
    noOfLines++;
    totalNoOfCharacters += temp.length(); //Rememeber this doesnot count the line termination character. So if you want to consider newLine as a character, add one in this step.
}

Answer 2

FileReader fr = new FileReader("pathtofile");
BufferedReader br = new BufferedReader(fr);
String line = "";
int cont=0;

while ((line = br.readLine()) != null) {
line = line.split("\\s+").trim();
cont+=line.length();
}

不要忘记关闭流并使用try catch。

Answer 3

最好先阅读 while 循环中的每个字符，然后首先检查文件的结尾，而不是尝试使用 for 循环。 e.g。

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

. . . .
. . . .

try
{
   BufferedReader reader = new BufferedReader(new FileReader("myFile.txt"));
   String textLine = reader.readLine();
   int count = 0;
   while (textLine != null)
   {
      textLine.replaceAll("\\s+",""); // To avoid counting spaces
      count+= textLine.length();
      textLine = reader.readLine();
   }
   reader.close();
   System.out.println("Number of characters in myFile.txt is: " + count);
}

catch(FileNotFoundException e)
{
    System.out.println("The file, myFile.txt, was not found");          
}

catch(IOException e) 
{
    System.out.println("Read of myFile.txt failed.");
    e.printStackTrace();
}

Answer 4

  Scanner scanner = new Scanner(yourfile);
  while(scanner.hasNext()){
        word = scanner.next();
        char += word.length();
  }

我应该如何在java中引用文本文件？

4 个答案: