AN OVERVIEW OF JAVA SERVER - SIDE FOR FRESHERS
While introducing Java language by Sun Microsystems Inc earlier, the aim was to embed greater usability into Web services. Java has invented this through the concept of web applets. Applet applications add functionality to Web pages, but because of compatibility problems and bandwidth issues, businesses solutions have started moving to server-side of Java. Java applets are programs that are conjugate directly into Web applications. When a web browser loads web page information which contains a reference to an applet, the applet byte-code will be downloaded to the client box and it will executed by the browser. This is quiet fine for very thin client applications, but when applets grow in size, the download time became unpredictable. Applets are also faced with browser compatibility issues more frequently. In order to run an applet in web, you must have a compatible browser. If your customer does not have a compatible browser, he can't get proper content. These problems have forced businesses solutions to take a look at Java Server-side. It solves the problems that applets face. When the code which is generated is being executed on the server-side, there are no problems with browser compatibility or issue related to download timings.
JAVA SERVLET:
Servlets are generic extensions or features to Java-enabled servers. Their most common function is to extend Web servers, providing a very robust, portable and secure way for programmers. A servlet is a dynamically retrieving module that services requests/responses from a Web server. As the servlet is running on the server side, it is not affected by the browser compatibility issues or Graphical User Interface conflicts.
PRACTICAL APPLICATIONS:
Servlets can be used for many kind of web based applications. The following are some examples in practical applications:
- Development of e-commerce has became one of the most common applications of Java servlets. A servlet can build an online based on the contents that are retrieved from database. It can then present this feature to the customer using dynamic/static HTML pages. The customer or the user will choose the items to be ordered, enter the price and billing information, and then sends the data to servlet side. When the servlet receives the request of posted data, it will process the orders and place them in the database for manipulations.
- Servlets is also used to deploy Web pages that open up wide legacy systems on the web. Lot of companies has their massive amounts of data stored on large frame databases. These businesses do not want to re-assemble their systems, so they choose to provide inexpensive and reliable Web features into them.
- When developing a distributed or dynamic object application that will be deployed to the Web, it runs into access restriction issues. If the user chooses to use applets in client browser, they can only able to open a connection to the initiating server, which might be under a firewall. Getting through a firewall using Remote Interface is a very common problem. If servlets are implemented, user can tunnel through the firewall using default HTTP Tunneling options.