Java NIO and TCP Connections: Difference between revisions

From NovaOrdis Knowledge Base
Jump to navigation Jump to search
Line 12: Line 12:
==Server==
==Server==


The server code uses a [[Java_Non-Blocking_I/O_Concepts#Selector|Selector]] to multiplex over two [[Java_Non-Blocking_I/O_Concepts#Selectable_Channel|selectable channels]]: a [[Java_Non-Blocking_I/O_Concepts#ServerSocketChannel|ServerSocketChannel]] that listens for incoming network connections and creates new [[Java_Non-Blocking_I/O_Concepts#SocketChannel|SocketChannels]] for each new TCP connection. Once a new connection is detected, the selector thread retrieves the corresponding SocketChannel and registers it with the same selector. The selector loop continues, and reacts to new connection attempts and new data coming over the existing SocketChannels.
The server code uses a [[Java_Non-Blocking_I/O_Concepts#Selector|Selector]] to multiplex over two [[Java_Non-Blocking_I/O_Concepts#Selectable_Channel|selectable channels]]: a [[Java_Non-Blocking_I/O_Concepts#ServerSocketChannel|ServerSocketChannel]] that listens for incoming network connections and creates new [[Java_Non-Blocking_I/O_Concepts#SocketChannel|SocketChannels]] for each new TCP connection.
 
The main event loop handles two types of events: new connections and data availability on the existing connections. Once a new connection is detected, the selector thread retrieves the corresponding SocketChannel and registers it with the same selector. If data becomes available on any of the registered SocketChannels, we use a [[Java_Non-Blocking_I/O_Concepts#Buffer|Buffer]] to read it.


==Client==
==Client==

Revision as of 18:43, 25 July 2018

Internal

Overview

This article describes the programming model involved in establishing a simple TCP connection and interacting with it with non-blocking I/O, from Java. We use Java NIO APIs primitives introduced in Java 4.

Programming Model

Server

The server code uses a Selector to multiplex over two selectable channels: a ServerSocketChannel that listens for incoming network connections and creates new SocketChannels for each new TCP connection.

The main event loop handles two types of events: new connections and data availability on the existing connections. Once a new connection is detected, the selector thread retrieves the corresponding SocketChannel and registers it with the same selector. If data becomes available on any of the registered SocketChannels, we use a Buffer to read it.

Client

JavaNIOAndTCPConnections.png

Example

Playground Java NIO and TCP Connections