Getting Started with HTML5 WebSocket on Oracle WebLogic 12c

The current release of Oracle WebLogic (12.1.2) added support to HTML5 WebSocket (RFC-6455) providing the bi-directional communication over a single TCP connection between clients and servers. Unlike the HTTP communication model, client and server can send and receive data independently from each other. 

The WebLogic server implementation has the following components:

•  The WebSocket protocol implementation that handles connection upgrades and establishes and manages connections as well as exchanges with the client. The WebLogic server fully implements the WebSocket protocol using its existing threading and networking infrastructure.
• The WebLogic WebSocket Java API, through the weblogic.websocket package, allows you to create WebSocket-based server side applications handling client connections, WebSocket messages, providing context information for a particular WebSocket connection and managing the request/response handshake. For additional information about the WebLogic WebSocket Java API interfaces and classes, visit the following resource: http://docs.oracle.com/middleware/1212/wls/WLPRG/websockets.htm#BABJEFFD
• To declare a WebSocket endpoint you use the @WebSocket annotation that allow you to mark a class as a WebSocket listener that's ready to be exposed and handle events. The annotated class must implement the WebSocketListener interface or extend from the WebSocketAdapter class.

When you deploy the WebSocket-based application on WebLogic, you basically follow the same approach using the standard Java EE Web Application archives (WARs), either as standalone or WAR module. Either way, the WebLogic Application Server detects the @WebSocket annotation on the class and automatically establishes it as a WebSocket endpoint.

Here is a simple application that creates a WebSocket endpoint at the /echo/ location path, receives messages from the client and sends the same message back to the client.

import weblogic.websocket.WebSocketAdapter;
import weblogic.websocket.WebSocketConnection;
import weblogic.websocket.annotation.WebSocket;

@WebSocket(pathPatterns={"/echo/*"})
public class Echo extends WebSocketAdapter{

@Override
  public void onMessage(WebSocketConnection connection, String msg){
      try{
          connection.send(msg);
      }catch(IOException ioe){
          //Handle error condition
      }
  }
}