What are the Differences Between `InputStream`, `DataInputStream`, and `BufferedInputStream` in Java?

What are the differences between `InputStream`, `DataInputStream`, and `BufferedInputStream` in Java?

In Java, `InputStream`, `DataInputStream`, and `BufferedInputStream` are classes that handle input stream operations, but they serve different purposes and functionalities. This explanation details their unique characteristics, use cases, and differences to help you understand when to use each class effectively.

import java.io.*;

public class StreamExample {
    public static void main(String[] args) throws IOException {
        // Example of InputStream
        InputStream inputStream = new FileInputStream("data.txt");

        // Example of DataInputStream
        DataInputStream dataInputStream = new DataInputStream(inputStream);
        int intValue = dataInputStream.readInt();

        // Example of BufferedInputStream
        BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
        byte[] buffer = new byte[1024];
        int bytesRead = bufferedInputStream.read(buffer);

        // Always close streams
        dataInputStream.close();
        bufferedInputStream.close();
    }
}

Causes

• `InputStream` is the superclass for reading byte streams, serving as a foundation for other specialized input streams.
• `DataInputStream` allows for reading Java primitive data types from an underlying input stream, providing methods for reading data in a portable way.
• `BufferedInputStream` adds a buffer to an input stream, allowing for more efficient reading by reducing the number of input operations.

Solutions

• Use `InputStream` when you need a general input stream without any specific format requirements.
• Use `DataInputStream` when you need to read binary data in the form of Java primitive types like int, float, or double.
• Use `BufferedInputStream` to enhance performance when reading data from streams with many small read operations.

Mistake: Not closing streams properly which can lead to memory leaks.

Solution: Always use try-with-resources or ensure to close your streams in a finally block.

Mistake: Using `DataInputStream` where non-primitive data types are expected.

Solution: Use `ObjectInputStream` for reading objects, not `DataInputStream`.

Mistake: Not using `BufferedInputStream` for frequent read operations which can result in poor performance.

Solution: Wrap your input streams with `BufferedInputStream` to optimize reading efficiency.