Java中文本文件中字母（az）的相對頻率計數

Question

我的文本輸入文件已經處理過，僅包含字母（az）和空格。 由於某些原因，當我輸入一個非常大的文本文件（大約40萬個單詞文件，該文件是通過剪切並粘貼到MSWord中確定的）時，相對頻率計數將失敗。 但是對於較小的文件，它可以工作，例如，總字符數= 36。 請有人能告訴我代碼在哪里出問題了嗎？

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

public class SoloCount {

public static void main(String[] args) throws IOException {
String inputFile = "sampleOutput.txt";


// My array for the a-z (97-122, based on ASCII table )

try {
int[] myArray = new int[26];
BufferedReader readerObject = new BufferedReader(new FileReader(inputFile));
String sCurrentLine="";
sCurrentLine = readerObject.readLine();

for(int i = 0; i<sCurrentLine.length(); i++)  // for each character in the readline                    from the input file, a-z will be counted.
        {
            if (Character.isLetter(sCurrentLine.charAt(i)) == true)     // qualifies characterisa letter and not an empty space.
            {
            char singleLetter = sCurrentLine.charAt(i);
            myArray[(int)(singleLetter)-97] = myArray[(int)(singleLetter)-97] + 1;  // Assigning frequency of a character. 97-122 represents a-z (ASCII table). e.g lowercase c = 97
            }
        }
        readerObject.close();


    //Calculate the total number of characters from the input file.
    double sumOfCharacters= 0;
    for (int i = 0; i < myArray.length; i++) 
    {
        sumOfCharacters += myArray[i];
    }
    System.out.println("The total number of characters in this file is: " + sumOfCharacters);

    //Calculating the realtive frequency.  Divide each occurrence for each letter (a-z) by the sumOfCharacters.
    System.out.printf("%10s%6s%n", "Letter", "%");   //column labels "Letter" and "%"
    System.out.println();
    for (int i = 0; i < myArray.length; i++) 
    {
        char singleLetter = (char)(i + 97);         //converting the decimal ASCII annotation to letters for a-z
        double value = myArray[i];
        System.out.printf("%8s%13f%n",singleLetter,(value/sumOfCharacters)*100);
    }

    } 
catch (FileNotFoundException e) {
        e.printStackTrace();
    }


}

}

Answer 1

您僅讀取文件的一行-可能是該行上只有36個字符，或者在36個字符之后有一個換行符。

您還可以通過傳入更大的初始緩沖區大小來增加BufferedReader的緩沖區大小-

BufferedReader readerObject = new BufferedReader(new FileReader(inputFile), 2048);

有關更多詳細信息，請參見此處 。