Telusko Docs

1. Introduction

Before the Scanner class was introduced (Java 5), BufferedReader was the most common way to read keyboard input in Java.
Many legacy applications, competitive programming environments, and high-performance systems still prefer BufferedReader due to its speed.

BufferedReader is faster than Scanner because:

It reads data as raw text.
It does not perform automatic parsing.
It buffers input, reducing I/O operations.

BufferedReader is part of the java.io package.

2. Importing BufferedReader

To use BufferedReader, you must import:

import java.io.BufferedReader;
import java.io.InputStreamReader;

BufferedReader needs InputStreamReader, which reads bytes from keyboard and converts them into characters.

3. Creating a BufferedReader Object

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

Explanation:

System.in → reads bytes from keyboard
InputStreamReader → converts bytes → characters
BufferedReader → reads characters efficiently

bufferreader

4. Reading Input with BufferedReader

BufferedReader reads strings only using:

String input = br.readLine();

To read numbers, you must convert the string manually.

5. Reading a String

System.out.print("Enter your name: ");
String name = br.readLine();
System.out.println("Hello, " + name);

6. Reading an Integer

Since BufferedReader reads only text, convert using Integer.parseInt().

System.out.print("Enter your age: ");
int age = Integer.parseInt(br.readLine());

7. Reading a Double

System.out.print("Enter your salary: ");
double salary = Double.parseDouble(br.readLine());

8. Reading a Character

BufferedReader does not have readChar(), so you extract the first char.

System.out.print("Enter your grade: ");
char grade = br.readLine().charAt(0);

9. Handling Exceptions

readLine() throws a checked exception → IOException. Hence, you must use try-catch or throws.

Method 1: Using throws

public static void main(String[] args) throws Exception {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String name = br.readLine();
    System.out.println(name);
}

Method 2: Using try-catch

try {
    String name = br.readLine();
} catch (Exception e) {
    System.out.println("Error reading input");
}

bufferreader

10. Closing BufferedReader

Although optional for console I/O, closing is a good practice.

br.close();

But avoid closing System.in in larger applications, as it cannot be reopened.

11. Full Example Program

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
    public static void main(String[] args) throws Exception {

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

        System.out.print("Enter name: ");
        String name = br.readLine();

        System.out.print("Enter age: ");
        int age = Integer.parseInt(br.readLine());

        System.out.print("Enter salary: ");
        double salary = Double.parseDouble(br.readLine());

        System.out.print("Enter grade (A/B/C): ");
        char grade = br.readLine().charAt(0);

        System.out.println("\n--- User Details ---");
        System.out.println("Name: " + name);
        System.out.println("Age: " + age);
        System.out.println("Salary: " + salary);
        System.out.println("Grade: " + grade);

        br.close();
    }
}

12. BufferedReader vs Scanner — Comparison

Feature	BufferedReader	Scanner
Speed	Faster	Slower (parsing overhead)
Input Type	Reads Strings only	Reads all data types directly
Conversion	Manual parsing required	Automatic parsing
Used For	Performance-critical apps	Simple input programs
Exception	Requires try/catch	No mandatory exception

13. Summary

BufferedReader is a fast and efficient way to read input.
It works with readLine() to read text.
You need to manually convert Strings to numbers.
Works well for large input or competitive programming.
Must handle exceptions using try-catch or throws.

Written By: Shiva Srivastava

Keyboard Input Using BufferedReader in Java