//i have to write a program that asks the user to enter the name of a file, and then asks the user to enter a character. the program
should count and display the number of times that the specified character appears in the file.
import java.util.Scanner; //Needed for Scanner Class
import java.io.*; //Needed for file classes
public class FileReader
{
private static String getFileContents(String fileName) {
File file = new File(fileName);
FileInputStream fio = null;
byte [] data = null;
String buffer = null;
try {
if (file.exists()) {
fio = new FileInputStream(file);
data = new byte[fio.available()];
fio.read(data);
buffer = new String(data);
} else
System.out.println("File (" + fileName + ") does not exist");
}
catch (Exception io) {
System.out.println(io.getMessage());
}
finally {
if (fio != null) {
try {
fio.close();
}
catch (Exception fioerror) {fioerror.getMessage();}
}
}
if (buffer==null)
buffer = "";
return buffer;
}
private static int countCharacters(String buffer, String testChr) {
int count = 0;
int startIndex = 0, sindex;
while ((sindex = buffer.indexOf(testChr, startIndex)) >= 0) {
startIndex = sindex+1;
count++;
}
return count;
}
private static int countCharactersInFile(String fileName, String testChr) {
String buffer = getFileContents(fileName);
return countCharacters(buffer, testChr);
}
public static void main(String[] args) throws IOException
{
String filename; //File name
String Char; // Character a-z or A-Z
//Create a Scanner object for keyboard input
Scanner keyboard = new Scanner(System.in);
//Get the Character from a-z or A-Z
System.out.print("Please enter a file to scan ?");
filename = keyboard.nextLine();
System.out.print("Please enter a character a-z or A-Z ?");
Char = keyboard.nextLine();
System.out.println("Count of character(" + Char + ") in file (" + filename + ") is " + countCharactersInFile(filename, Char));
}
}