- Next Steps of the Elaboration Phase
- Separating Services
- Logical versus Physical Tiers
- Tier Strategy
- Managing Transaction Scope
- Incorporating the Internet into the Solution
- More about the Web Interface
- Remulak Productions' Execution Architecture
- Checkpoint
This chapter is from the book
This chapter is from the book
This chapter is from the book
Incorporating the Internet into the Solution
As stated early in the book, all of our implementation will utilize a light browser-based client front end:
The Presentation Services layer will use a light Web-based front end that will use simple HTML and JavaScript communicating with a Web-based back end for all the pathways supported in the application. There will be a servlet on the Web server to act as a broker to both JavaBeans using native JDBC and JavaServer Pages, as well as an implementation using Enterprise JavaBeans and JavaServer Pages. Alternatively, we could use a Java applet or even a Java application to talk to the servlet (yes, you can send and receive information from a Java application to a servlet via a DataOutputStream object and an InputStreamReader object, respectively; however, the act of parsing the returned information from the servlet would be too cumbersome for our application).
The Business Services layer will reside on the server and will use a servlet and JavaServer Pages as the intermediary for the Web client, as well as both JavaBeans and Enterprise JavaBeans to manage the entity classes (as described earlier). Our use-cases and their pathways will be implemented with control classes. In the servlet/JSP/JavaBean solution, the controller will be simply a JavaBean. In the servlet/JSP/EJB solution, the controller will be a session EJB.
The Data Services layer will be implemented with both JavaBeans/ JDBC and the EJB framework. Both CMP and BMP implementations will be explored for Remulak in Chapter 12. Prior to EJB 2.0, CMP implementations varied widely across EJB products, leading to less portability and perhaps resulting in fewer implementations utilizing this feature. EJB 2.0, among other features, vastly improved the capabilities of CMP, making it much more of a viable design alternative.
Remulak Productions, however, cannot dictate which Web browser a client will use, so we will test the application's functionality using the two most common browsers: Microsoft Internet Explorer and Netscape Navigator.