BufferedReader and StringTokenizer

The StringTokenizer class in java.util can be used to parse a line of integers. Here is a Java program that reads a line of integers, displays each integer, and then calculates and displays the sum of all the integers.

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.StringTokenizer;

public class IntegerProcessor {

    public static void main(String[] args) {

        BufferedReader reader = null;

        try {

            // Read input from the console

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

            System.out.println("Enter a line of integers separated by spaces:");

            String line = reader.readLine();

            // Use StringTokenizer to parse the line of integers

            StringTokenizer tokenizer = new StringTokenizer(line);

            int sum = 0;

            System.out.println("The integers are:");

            while (tokenizer.hasMoreTokens()) {

                String token = tokenizer.nextToken();

                int number = Integer.parseInt(token);

                System.out.println(number);

                sum += number;

            }

            // Display the sum of all integers

            System.out.println("The sum of all integers is: " + sum);

        } catch (IOException e) {

            System.err.println("An IOException occurred: " + e.getMessage());

        } finally {

            // Close the BufferedReader

            if (reader != null) {

                try {

                    reader.close();

                } catch (IOException e) {

                    System.err.println("Failed to close BufferedReader: " + e.getMessage());

                }

            }

        }

    }

}

Explanation:

1. BufferedReader: Used to read a line of input from the console.
2. StringTokenizer: Used to parse the line of integers separated by spaces.
3. Parsing and Processing: The StringTokenizer splits the input line into tokens (integers). Each token is parsed to an integer, printed, and added to the sum.
4. Exception Handling: Handles IOException that might occur during reading.
5. Finally Block: Ensures that the BufferedReader is closed properly.

Detailed Steps:

1. Reading Input:

   • The program reads a line of integers from the console using BufferedReader.

2. Using StringTokenizer:

   • The StringTokenizer object is created with the input line.
   • The while loop iterates through each token, converts it to an integer, prints it, and adds it to the sum.

3. Displaying Results:

   • After processing all tokens, the program prints the sum of all integers.

4. Exception Handling:

• The try block handles the input operations and catches any IOException.
• The finally block ensures that the BufferedReader is closed properly to release the resources.

Programs to Try:

Find the sum of even and odd integers separately