Java BufferedReader

BufferedReader and BufferedWriter

BufferedReader and BufferedWriter make reading and writing text files faster.

• BufferedReader lets you read text line by line with readLine().
• BufferedWriter lets you write text efficiently and add new lines with newLine().

These classes are usually combined with FileReader and FileWriter, which handle opening or creating the file. The buffered classes then make reading/writing faster by using a memory buffer.

Read a Text File (Line by Line)

Use BufferedReader with FileReader to read each line of a file:

Example

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class Main {
  public static void main(String[] args) {
    try (BufferedReader br = new BufferedReader(new FileReader("filename.txt"))) {
      String line;
      while ((line = br.readLine()) != null) {
        System.out.println(line);
      }
    } catch (IOException e) {
      System.out.println("Error reading file.");
    }
  }
}

Comparing File Reading Classes

Java gives you several ways to read files. Here's when to pick each one:

• Scanner - best for simple text. It can split text into lines, words, or numbers (e.g., nextInt(), nextLine()).
• BufferedReader - best for large text files. It is faster, uses less memory, and can read full lines with readLine().
• FileInputStream - best for binary files (like images, PDFs, or audio)