I/O Streams

 Input/Output Streams in Java

In Java, streams represent a sequence of data. Input streams are used for reading data from a source, while output streams are used for writing data to a destination.

Types of Streams:

1. Byte Streams:

   - Operate on bytes.

   - Suitable for binary data.

   - `InputStream` and `OutputStream` are the abstract classes for byte streams.

2. Character Streams:

   - Operate on characters, internally converting them to bytes.

   - Suitable for text data.

   - `Reader` and `Writer` are the abstract classes for character streams.

Commonly Used Byte Streams:

- `FileInputStream` and `FileOutputStream`: For reading/writing from/to files.

- `ByteArrayInputStream` and `ByteArrayOutputStream`: For reading/writing to byte arrays.

- `DataInputStream` and `DataOutputStream`: For reading/writing primitive data types.

- `ObjectInputStream` and `ObjectOutputStream`: For reading/writing Java objects.

Commonly Used Character Streams:

- `FileReader` and `FileWriter`: For reading/writing text files.

- `BufferedReader` and `BufferedWriter`: For reading/writing text with buffering for efficiency.

- `InputStreamReader` and `OutputStreamWriter`: For bridging byte and character streams.

Basic Usage Pattern:

1. Opening Streams:

   - Create a stream object by passing the appropriate source or destination as a parameter to its constructor.

2. Reading/Writing Data:

   - Use methods like `read()`, `write()`, `readLine()`, `writeLine()`, etc., to perform I/O operations.

3. Closing Streams:

   - Always close streams after use to release system resources.

   - Use `close()` method or utilize try-with-resources statement for automatic resource management.

Example:

import java.io.*;

public class StreamExample {

    public static void main(String[] args) {

        try (FileInputStream fis = new FileInputStream("input.txt");

             FileOutputStream fos = new FileOutputStream("output.txt")) {

            

            int byteRead;

            while ((byteRead = fis.read()) != -1) {

                fos.write(byteRead);

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}