Module# 12: Java IO Streams and File Lecture#44: IO with Character Streams

// Example 44.1: Reading String, Integer and Double from Keyboard

import java.io.*;

public class KeyboardReading{

public static void main(String args[]) throws IOException {

BufferedReader b = new BufferedReader(new InputStreamReader(System.in));

System.out.println("Enter a String: ");

String str1 = b.readLine();

System.out.println("Entered String value is: " + str1);

System.out.println("Enter a whole number: ");

String str2 = b.readLine();

int x = Integer.parseInt(str2);

System.out.println("Enter a double value: ");

String str3 = b.readLine();

double y = Double.parseDouble(str3);

if(x > y)

System.out.println("First number " +x + " is greater than second number " + y);

else

System.out.println("First number " +x + " is less than second number " + y);

b.close();

}

}

// Example 44.2: Calculator using BufferedReader

import java.io.*;

class InterestCalculator {

public static void main(String args[ ] ) {

Float principalAmount = new Float(0);

Float rateOfInterest = new Float(0);

int numberOfYears = 0;

BufferedReader b = new BufferedReader(new InputStreamReader(System.in));

String tempString;

System.out.print("Enter Principal Amount: ");

System.out.flush();

tempString = b.readLine();

principalAmount = Float.valueOf(tempString);

System.out.print("Enter Rate of Interest: ");

System.out.flush();

tempString = b.readLine();

rateOfInterest = Float.valueOf(tempString);

System.out.print("Enter Number of Years:");

System.out.flush();

tempString = b.readLine();

numberOfYears = Integer.parseInt(tempString);

// Input is over: calculate the interest

int interestTotal = principalAmount*rateOfInterest*numberOfYears;

System.out.println("Total Interest = " + interestTotal);

}

}

// Example 44.3: Copying files using FileReader and FileWriter

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

public class CopyChars {

public static void main(String[] args) throws IOException {

FileReader inputStream = null;

FileWriter outputStream = null;

try {

inputStream = new FileReader("nptel.txt");

outputStream = new FileWriter("characteroutput.txt");

int c;

while ((c = inputStream.read()) != -1) {

outputStream.write(c);

}

} finally {

if (inputStream != null) {

inputStream.close();

}

if (outputStream != null) {

outputStream.close();

}

}

}

}