Introduction
The
latest release of JDeveloper 12c (12.1.3.0) along with WebLogic Server
12.1.3 came up with some new Java EE 7 features. One of them is support
of JSR 356 Java API for WebSockets. Actually the WebSocket Protocol (RFC
6455) has been supported starting from 12.1.2.0 release, but it was
based on WebLogic specific implementation of the WebSocket API. Now this
proprietary WebLogic Server WebSocket API has been deprecated. However,
it is still supported for backward compatibility.
In this post I am
going to show an example of using JSR 356 Java API for WebSockets in a
simple ADF application. The use case is about some sailing regatta which
takes place in the Tasman Sea. There are three boats participating in
the regatta and they are going to cross the Tasman Sea sailing from
Australia to New Zealand coast. The goal of the sample application is to
monitor the regatta and inform users about how it is going on, showing
the positions of the boats on a map.
We're going to declare a
WebSocket server endpoint in the application and when a user opens a
page a Java script function opens a new WebSocket connection. The
application uses a scheduled service which every second updates boats
coordinates and sends a message containing new boats positions to all
active WebSocket clients. On the client side a Java script function
receives the message and adds markers to the Google map according to the
GPS coordinates. So, each user, interested in the regatta, is going to
see the same updated picture representing the current status of the
competition.
WebSocket server endpoint
Let's start with declaring a WebSocket server endpoint. There is a small issue in the current implementation, which probably will be resolved in future releases. The WebSocket endpoints can not be mixed with ADF pages and they should be deployed in a separate WAR file. The easiest way to do that is to create a separate WebSocket project within the application and to declare all necessary endpoints in this project:
This is also important to set up a readable Java EE Web Context Root for the project: Read the complete article here.
For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.
