What is Java Nio ?

Java Nio is Java Non-Blocking IO package which allows for reading and writing information from IO devices without having any blocking or wait status , leading to optimized interactions

Components of Java Nio

• Channels

  All IO in NIO is via channels. Channels act as streams and we can “read” data from Channels into Buffers and “write” data from Buffers into Channels

IO is managed via the following implementations

 - Files 
 - UDP/TCP

Extending the above to NIO results in the following channel implementation

- FileChannel
- DatagramChannel for UDP 
- SocketChannel for TCP
- ServerSocketChannel

• Buffers

Buffer is a placeholder in memory for data consumed from a channel or data which is about to be written back on the channel. Buffers take data from the IO devices, in form of primitive data type streams.

Main type of primitive data-types are

- Char
- Byte
- Double
- Integer
- Long
- Short

Extending the above for NIO

- CharBuffer
- ByteBuffer
- DoubleBuffer
- IntegerBuffer
- LongBuffer
- ShortBuffer

• Selectors

Selector allows a single thread to manage traffic coming from multiple channels. So effectively selector is the glue between the Channels and the Buffers and it binds the two on a single thread.