MultiCharSearch.java

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MultiCharSearch 
{
    public static void main(String[] args) 
    {
        String filePath ="C:\\Users\\sami0\\OneDrive\\Documents\\Downloads\\KEGGdatabase.txt"; // Change this to the path of your file
        String charactersToSearch = "agtc"; // Characters you want to search for

        // Initialize counters for each character
        int countA = 0, countT = 0, countC = 0, countG = 0;

        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) 
        {
            String line;
            Pattern pattern = Pattern.compile("[" + charactersToSearch + "]"); // Create regex pattern

            while ((line = br.readLine()) != null) 
            {
                Matcher matcher = pattern.matcher(line);
                while (matcher.find()) 
                {
                    char foundChar = matcher.group().charAt(0);
                    switch (foundChar) 
                    {
                        case 'a': countA++; break;
                        case 't': countT++; break;
                        case 'c': countC++; break;
                        case 'g': countG++; break;
                    }
                }
            }
            float totl=countA+countT+countC+countG;
            float perA=(countA/totl)*100;
            float perT=(countT/totl)*100;
            float perC=(countC/totl)*100;
            float perG=(countG/totl)*100;

            // Display the count of each character
            System.out.println("A content : " + countA );
            System.out.println("A content(%) : " + perA + "%");
            System.out.println("T content : " + countT );
            System.out.println("T content(%) : " + perT + "%");
            System.out.println("C content : " + countC );
            System.out.println("C content(%) : " + perC + "%");
            System.out.println("G content : " + countG );
            System.out.println("G content(%) : " + perG + "%");
        } 
        catch (IOException e) 
        {
            e.printStackTrace();
        }
    }
}