Define byte stream and character stream. Write a program to read...

Byte Stream vs Character Stream in Java (with Program to Read a File)

Definitions

Byte Stream: Works with raw 8-bit bytes. It is used for reading and writing binary data such as images, audio, PDFs, or any non-text content. Core abstract classes: InputStream and OutputStream (e.g., FileInputStream, BufferedInputStream).
Character Stream: Works with 16-bit Unicode characters. It is used for reading and writing text data and can handle character encoding properly. Core abstract classes: Reader and Writer (e.g., BufferedReader, FileReader, InputStreamReader).

Key Differences

Data type: Byte streams handle bytes; character streams handle characters.
Use case: Use byte streams for binary files; use character streams for text files.
Encoding: Byte streams do not deal with encoding; character streams can handle encoding (e.g., UTF-8) via readers/writers.

Program 1: Read Text File Using Character Streams (Recommended for Text)

This program reads a text file line by line using BufferedReader with UTF-8 encoding and prints its contents to the console.

// File: ReadTextFileChar.java
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.io.IOException;

public class ReadTextFileChar {
    public static void main(String[] args) {
        if (args.length == 0) {
            System.out.println("Usage: java ReadTextFileChar <path-to-text-file>");
            return;
        }

        String path = args[0];

        try (BufferedReader br = new BufferedReader(
                 new InputStreamReader(new FileInputStream(path), StandardCharsets.UTF_8))) {

            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }

        } catch (IOException e) {
            System.out.println("Error reading file: " + e.getMessage());
        }
    }
}

Program 2: Read File Using Byte Streams (Works for Any File)

This program reads raw bytes using FileInputStream and writes them directly to the console output stream.

// File: ReadFileBytes.java
import java.io.FileInputStream;
import java.io.IOException;

public class ReadFileBytes {
    public static void main(String[] args) {
        if (args.length == 0) {
            System.out.println("Usage: java ReadFileBytes <path-to-file>");
            return;
        }

        String path = args[0];
        byte[] buffer = new byte[4096];

        try (FileInputStream fis = new FileInputStream(path)) {
            int bytesRead;
            while ((bytesRead = fis.read(buffer)) != -1) {
                // Write raw bytes to standard output
                System.out.write(buffer, 0, bytesRead);
            }
        } catch (IOException e) {
            System.out.println("Error reading file: " + e.getMessage());
        }
    }
}

How to Compile and Run

javac ReadTextFileChar.java
java ReadTextFileChar input.txt

javac ReadFileBytes.java
java ReadFileBytes input.txt

Tips for B.Tech CSE Students

Use character streams for text to avoid encoding issues; specify StandardCharsets.UTF_8 when possible.
Use byte streams for binary files (images, PDFs); do not convert bytes to String for binary data.
Prefer try-with-resources to automatically close streams and prevent resource leaks.

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