【Summary】
The increasing popularity and deepening of Internet applications, providing a broad activity stage for Java technology, and also greatly advised Browser / Server mode of corporate intranet application and network computing.
As a technical backbone in a information company, I have been able to undertake a development task such as a bank credit management and inquiry system, independently completing the system design, class design, partial development and testing.
The entire system is fully designed in accordance with J2EE standards. The front interface applies JSP technology. The control section uses servlet to develop, and the business logic applies EJB technology to encapsulate. The application server uses the WebLogic, which supports J2EE standard BEA's WebLogic. The database is INFORMIX 7.3, the purpose is to Keep consistent with other business system databases in the bank. On the hardware platform, we choose a medium-sized server machine for HP, and the operating system is HP-UX.
The system interface is applied to IE, which is not only compatible, but also is familiar with the majority of users. After the system is running, the various branches are generally reflected in the world's friend, powerful, and the effect is satisfactory.
【text】
Private savings in bank applications, business accounting, international business, credit, financial management are all important, and they constitute a bank's basic business system. The credit business I have developed is an important part of the source of bank profits. Different with savings, business models mainly based on trading matters, although credit is also transaction, but more other auxiliary information is required. Such as the basic information of the customer, in the business situation, credit rating, whether there is overdue loans that fail to return. All branch of relevant business personnel and branch managers want to be able to understand this information in a timely manner. The traditional terminal-based user interface is difficult to pass so much information to the user, so we decided to adopt the user interface based on the beta IE. On the one hand, IE uses easy to use, no special training, and it is bundled with the Windows operating system. It also saves the front desk fee. There is ASP in development technology, and JSP is available.
Since Java technology has developed rapidly on the Internet, J2EE has put forward a new idea to unify platforms, so we decided to adopt J2EE standards and selected JSP. In the design, it is basically a transaction screen corresponding to a JSP program, and gives full play to the strength of the JSP dynamic processing page.
In order to make the design have better exparative, flexibility and logic, it can lay a solid foundation for future expansion, I use the MVC design mode of Modelu, View, Controller, and the View is implemented by JSP, while Controller It is a servlet program that is responsible for handling all the requests transmitted by the front desk, and distributes the corresponding JSP program to process according to the predetermined path / program relationship. Since servlet is designed for Java server-side programming, it is quite appropriate by it to be responsible for server-side processing.
When you start design, I use the component technology, and the EJB assumes the Modelu role of the design pattern. Specific loans account, lending, surplus loans, returning loans, etc., there is a specific EJB. In order to separate these processing logic to the corresponding database operation, it is more convenient to maintain, and I will handle the EJB of the service to session beans, and the corresponding Entity bean is used to access the background database. . It is important to inquire, according to the results of demand analysis, and the goal is to increase the speed of the query as much as possible.
In the access to the database, I originally designed the Driver Manager belled in Informix JDBC, so that Driver and Server write Driver and Server in the BEAN in the access database, and later considering that the platform should be used independently. After seeing the instructions of the JDBC part in J2EE, the Data Resource method is changed, so that even if the database is replaced in Oracle or other products, the program does not have to be modified, only need to change when configured. During the development of this credit management system, Java's platform was unrelated, and it was performed in the activities developed in development. Due to the relatively shortage of funds, our development environment is a HP machine for each project group. Although each development team has built its own environment, there are more projects, especially in the event and bulk test, the machine It is obsessed that the efficiency of development and testing is greatly reduced. Since our team is Java technology, our group can build the same environment on its own NT machine. In this way, everyone usually develops, including JSP, servlet, EJB program, can be done locally, just to put it on the HP development machine to the test or presentation phase.
Web applications we developed before, often applied part of Web technology, such as adopting Apache Web Server, ASP development language, etc. The integration and combination of the entire system is often undesirable. This time because of a complete set of J2EE standards, the synergy and consistency of the entire system are very good. Coupled with an application server that supports J2EE - Bea WebLogic, we have done an unsatisfactory complicated configuration, and the inter-module is not worried, just in the graphical configuration tool, enter The configuration required by the system, such as the relationship between the path and the actual application, EJB reference in the component, Data Resource, etc. After all configuration is complete, WebLogic will complete the deployment of the project for us, and package all of this related program. stand up.
It turns out that the documentation task of our development group is very heavy, because the entire system has both transaction section, and there are many management inquiry, transaction, and data and source programs. In order to solve this problem, we directly applied JavaDoc export documents in the Java source, not only the text is beautiful, but also keeps the consistency with the source program, it is a stone two birds.
After the entire project is complete, the user feels friendly and easy to operate. But I know in my heart. There are still many ways that can be improved in this system.
First, based on the development of the Java system requires more funds, the system is limited by the system, only the production machine is applied, so that Web Server, Application Server, DB Server can only be crowded together. Although WebLogic can achieve partial load balancing, such distribution is definitely not the most ideal in future business development. Fortunately, we have considered good scalability while designing, in the later conditional permit, only further deployment between different machines can be made, and the application is generally no longer need to be changed.
Second, in the design, UML products can be used, such as Rational Rose, on the other hand, Rational Rose has automatic code generation functions, or greatly saving costs.
Finally, the current amount of credit management system is not much more than the number of users. When promoting similar systems requires a large number of users, Java-based system-based response time and system distribution will have a more prominent contradiction. These are all where I need to pay attention in the future system design and development, and it is also the direction in which Java technology should work. (This article mainly refers to the paper of Shanghai Dai Ling Pan.)
Comment: Discuss specific, deeper application, clear expression. The problem is true.
