Using array to count letters in a particular text file..(java)

This program is used in counting letters in particular text.It counts the frequency of each letter e.g z= 30, c=20. and prints the results.I managed to work out part of it. the main problem came in when counting the letters using arrays.. while i was trying to compile it..there was a problem with line i have highlighted(****). could any of u assist with this. and maybe if there is another problem..jus point out or assist..

import java.io.*;

public class BufferedReaderTest {

  public static void main(String args[]) throws Exception {
    char[] capital = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J','K', 'L', 'M', 'N',
                      'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};

    FileReader fr = new FileReader("watu.txt");
    BufferedReader buffer = new BufferedReader(fr);
   
    String inString;

    while ((inString = buffer.readLine()) !=null) {
       String upperCase = inString.toUpperCase();
       System.out.println(upperCase);
     }
       int nextChar;
               char ch;
               int count=0;
            for (int i = 0; i < 26; i++)
            {


     while ( (nextChar = inString.read() ) != -1 ) ***problem with this line**
     {

     ch = (char) nextChar;
     if( ch== capital[i])
     {
      count++;
                }

     }
       System.out.print("  " + capital[i]);
       System.out.println("          " + count);


     fr.close();
     }
   }
  }