feat: add ByteStreamExample1 using ByteArrayInputStream with readAllBytes()

WHAT:
- Implemented `ByteStreamExample1` to demonstrate reading all bytes from a
  `ByteArrayInputStream` at once.
- Created a byte array of characters ('a' through 'j').
- Used `readAllBytes()` to retrieve the entire byte stream in a single call.
- Converted the byte array into a String for display.
- Closed the stream after reading.

WHY:
- `readAllBytes()` (Java 9+) provides a convenient way to consume the entire
  contents of a stream at once, instead of looping byte-by-byte.
- Demonstrates how in-memory byte arrays can be efficiently turned into
  strings or processed as a whole.
- Simplifies scenarios where the data size is small and known in advance.

HOW:
1. Declared a byte array containing ASCII characters 'a' through 'j'.
2. Passed it to a `ByteArrayInputStream` to simulate an input stream source.
3. Called `readAllBytes()`, which:
   - Reads all remaining bytes from the stream until end-of-stream.
   - Returns them as a new byte array.
4. Wrapped the result in a `String` constructor to convert to a readable string.
5. Printed the string (`abcdefghij`) to the console.
6. Explicitly closed the stream (though `ByteArrayInputStream`'s `close()`
   is effectively a no-op).

REAL-WORLD USE CASES:
- Reading in-memory binary data (e.g., network packets, cached files).
- Parsing test data without external file dependencies.
- Simplifying conversions of byte streams to Strings in small/medium-size inputs.
- Useful in mocking InputStreams for unit testing I/O-heavy code.

NOTES:
- `ByteArrayInputStream` supports `mark()` and `reset()` operations fully.
- Best for small datasets since `readAllBytes()` loads everything into memory at once.
- For very large streams, prefer reading in chunks with a buffer.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section23JavaIOStreams/src/ByteStreamExample1.java

@@ -3,11 +3,13 @@
 public class ByteStreamExample1 {
     public static void main(String[] args)throws Exception {
         byte b[]={'a', 'b','c','d','e','f','g','h','i','j'};
+
         ByteArrayInputStream bis = new ByteArrayInputStream(b);
 
         //Reading all bytes together.
         String str = new String(bis.readAllBytes());
+
         System.out.println(str);
         bis.close();
     }
-}
+}