The formation of development team in Java EE project

J2ee| Project Java This application model allows different developers to develop elements at the same time. Here is a description of the different levels of design staff, developers of technical requirements. Describe the following categories.
Designers build a team
Team roles that represent the logical layers
Team roles such as business logic layer
The team role of the database access layer

The composition of a team can be based on the number of people and the size of the system. For example, not all roles have to be assigned, and some can play the role they cannot.

Designer
In the development of component-based application systems, one or several people must have a comprehensive understanding of the overall requirements of the system, such as the control process of the system, and other interfaces, and so on. Some companies call the role chief engineer, and whatever it is, the role is important, and he undertakes to coordinate the work between different development teams to help them consider the "big picture" of the system.

Team roles that represent the logical layers
In the presentation layer, the user interface is dynamically generated. The following developers are required:
Java servlet Developers
JSP Developers
HTML Design Staff
Art Staff
JavaScript developer for Client
The Servlet developer builds the logic of the presentation layer, while the other person builds the form of performance.

Java Servlet Developers
The servlet handles browsing between pages and pages, session management, and simple input validation. The servlet also joins the elements of the business logic.
Servlet developers must understand a number of related issues, HTTP requests, security, multilanguage, and some page elements such as session, cookies, timeouts, and so on. In the application of Java EE, the servlet must be written in JavaScript, and the servlet may invoke JSP, EJB, JDBC, and so on. As a result, servlet developers work closely with other people in the application system.

JSP Developers
JSP developers work closely with servlet developers to define the performance layer pages of the system. Even in complex development projects, the developers of JSP and servlet may be one person.


However, if most Java in a system is in a servlet rather than in a JSP, the JSP staff does not have to be familiar with Java.

HTML Design Staff
HTML designers optimize HTML pages. For example, he might want to complete the following tasks:

Ensure that all pages are displayed correctly in different browsers
Ensure low speed modem access is not affected
Further optimizing the JSP designer's page

Art Staff
Artists create pictures, and so on. These images need to be small and fast to download. The artist works closely with the HTML page staff.

JavaScript developer for Client
There are many reasons to use JavaScript for the client. For example, you can handle simple input validation, not to the server, but also to make the user interface more vivid. This role works closely with the servlet, JSP staff.

Team roles in the business logic layer
The business logic layer contains business rules and business entities. The following people are required:
Session Bean Developer
Entity Bean Developer

Session Bean Developer
Session beans contains the logic of business processes and business rules. For example, a session bean might be designed to calculate the tax rate for a check. If a system is confronted with complex logic that frequently changes and uses session beans heavily, the result is that session beans need to be constantly updated.

The developer of the session bean is generally an expert in the field, understanding complex, specialized domain logic, and data validation rules. This person works closely with the servlet and entity bean developers.

The session bean may need to invoke the JDBC interface, and other EJBs. The stateless session bean system runs better. Because if the calculated rate is a stateful session bean, the system must access a server that holds the state information of the bean. If that server happens to have a problem, the entire process is blocked.

Entity Bean Developer
The Entity bean represents a permanent object, such as a record in a database. The task of the Entity bean developer is to design an organization chart of all the business data that is object-oriented. Creating an object-oriented attempt means mapping a table in a database (a relational type) to a entity bean. For example, the developer needs to convert the Customer table, invoice table, and order form to the corresponding customer, invoice, and order object.


A entity Bean developer works closely with the session bean, the servlet developer, to ensure that application systems provide fast, flexible, scalable access to business data.

The Entity bean may invoke a large number of JDBC interfaces. There are few calls between entity beans.

The team role of the database access layer
In the database access layer, developers need to establish a relational database of the ER diagram, data dictionary and so on related documents. All modifications to the database, access, and so on, are done through the database Access layer developer. This role assumes the role of DBA in most projects.

After the team is built, you can start designing the user interface.

Designing the User interface
It is recommended to design the application system from the front to the beginning. That is, it is most efficient to design the user interface first and then design the EJB.