Java Servlet technology provides Web developers with a simple, consistent mechanism for extending the functionality of a Web server and for accessing existing business systems. A servlet can almost be thought of as an applet that runs on the server side–without a face. Java servlets make many Web applications possible.
The Servlet arrangement has not undergone any major kinds of changes. The freshly added functions such as the web application events, filters and the Servlet specification are the ones that didn’t undergo considerable changes. However the major specifications and features of the system have stayed strong and the new release of the Servlet 3.0 will cause a major variation in the way most web developers design their Java applications.
Now, let’s get a bit into the skin of the new features added in Servlet 3.0. Herein we shall get in touch with aspects like, ways to plug framework, adding libraries to any web application through the use of web fragments, asynchronous processing and its other features. Servlet 3.0 supports the asynchronous processing method – a unique useful feature of the AJAX applications. In the usual conditions, when making a request the servlet generates a thread that has to pause for a while in order to avail a response from its resource. Only once this is completed, the next operation can be followed on the thread. The asynchronous processing feature comes handy in this situation. Asynchronous processing prevents this type of blocks by simply allowing the servelet thread to continue with the next operation.
The Servlet 3.0 has three basic goals for all its developers who use the system. These features are simplicity, the ease to use for development and and lastly adherence to the principles of web 2.0.
Another feature is that of its pluggability. This feature makes the web applications modular and also easier to maintain. Implemented through web fragments, plug ability relieves the developer from making too many Servlet configuration entries in the web.xml file. When you make use of any third party framework like that of JSF, Spring, or Struts, you also require a parallel entry in web.xml for its servlet.