1、 一种基于 Hibernate和 Struts的 J2EE应用开发策略 This text analysis the mechanism of Hibernate and Struts, put forward 1 kind EE according to the J2 of the Hibernate and the Struts application development strategy.In this kind of strategy, the model layer use a Hibernate realization and see diagram and controlle
2、r to then use a Struts frame a realization.So can consumedly lower the development efficiency that the Ou of code match sex and exaltation system. The key word Hibernate, Struts, the MVC, hold out for long time a layer one preface along with the Java technique of gradual mature and perfect, Be estab
3、lishment business enterprise class application of standard terrace, the J2 EE terrace got substantial of development.Several technique asked for help from to include in the J2 EE norm:Enterprise JavaBean(EJB), Java Servlets(Servlet), Java Server Pages(JSP), Java Message Service(JMS).etc., developmen
4、t many application system.But, also appeared some problem in the tradition J2 the EE the application of the development the process:1)the antinomy of of data model and logic model.Currently the database of usage basically and all is relation type database, but the Java be essentially a kind of the l
5、anguage which face to object, object at saving with read usage SQL and JDBC carry on a database operation and lowered plait distance of efficiency and system of can maintenance；2)tradition of J2 EE application much the adoption is according to the EJB heavy weight frame, this kind of frame suitable
6、for develop a large business enterprise application, but usage the EJB container carry on development and adjust to try to need to be waste a great deal of time.For lowering the Ou of code to match sex, exaltation system of development efficiency, this text put forward 1 kind EE according to the J2
7、of the Struts frame and the Hibernate frame application development strategy. 2 datas holding out for long time layer and Hibernate is one piece according to hold out for long time layer frame, is a kind of realization object and relation of the tool which reflect to shoot(O/R Mapping), it carried o
8、n the object of the lightweight to pack to the JDBC and make procedure member can usage object plait distance thought to operation database.It not only provided to shoot from Java to reflect of data form, but also provided a data a search and instauration mechanism.Opposite in usage JDBC and SQL to
9、operation database, use a Hibernate ability consumedly of exaltation realization of efficiency.The Hibernate frame use allocation document of the form come to the reflect of the definition Java object and data form to shoot relation, in the meantime at more deep of level of data form of relation exp
10、lanation for the relations such as inherit of and containment etc. of Java object.Pass the usage HQL language sentence complications of relation the calculate way use the way of object description, to a large extent simplification logarithms according to of search, speed development of efficiency.Ha
11、ve in the Hibernate a simple but keep the API of view, used for to the database mean of object performance search.Want to establish or the modification be these objects, need in the procedure carry on with them to hand over with each other, then tell Hibernate to keep.So, a great deal of pack hold o
12、ut for long time turn operation of business logic no longer demand write a trivial JDBC language sentence, make data last long thus the layer got biggest of simplification. 3 use the Struts realization MVC structure MVC(Model-View-Controller) is put forward by the Trygve Reenskaug, first drive appli
13、cation in the environment SmallTalk-80, is many to hand over with each other with interface system of constitute foundation.According to the need of variable of the interface design, MVC hand over with each other constitute of system to resolve into model and see diagram, controller three part. Mode
14、l(Model) is software processing problem logic at independence in outside manifestation under contents and form circumstance of inside abstract, packed the core data, logic of problem and function of calculation relation, independence in concrete of interface expression and I/O operation.See diagram(
15、View) mean information and particular form demonstration of model data and logic relation and appearance to the customer.It acquire a manifestation information from the model, there can be many for homology of information dissimilarity of manifestation form or see diagram.The controller(Controller)
16、is a processing the customer hand over with software with each other operation of, its job is control provide model in any variety of dissemination, insure a customer interface among the model of rightness should contact；It accept a customer of importation, give the importation feedback model, then
17、realization compute model control, is make model and see diagram to moderate work of parts.Usually 1 see a diagram rightness should a controller.Model, see separate of diagram and controller, make a model be able to have many manifestation to see diagram.If the customer pass a certain see the contro
18、ller of diagram change the data of model, all other dependence in these see of data diagram all should reflection arrive these variety.When therefore and regardless occurrence what data variety, controller all would variety notice allly see diagram, cause manifestation of renewal.This is actually a
19、kind of variety of model-dissemination mechanism. The Struts frame is to be the item of Apache Jakarta to constitute part to publish luck to do at the earliest stage, it inheritted MVC of each item characteristic, and did according to the characteristics of J2 EE correspond of variety with expand.Th
20、e Struts frame was good to combine Jsp, Java Servlet, Java Bean, Taglib etc. technique.In the Struts, what to undertake the controller role in the MVC be an ActionServlet.The ActionServlet is an in general use control module.This control module provided a processing all HTTP claim which send out Str
21、uts of entrance point.Its interception with distribute these claim to arrive correspond of action type.(these action all of type is Action son type)Moreover the control module is also responsible for using to correspond of claim the parameter fill Action Form(FromBean), and pass action type(ActionBe
22、an).Action type the business logic of the interview core, then interview Java Bean or adjust to use EJB.End action type control the power pass follow-up of JSP document, from JSP document born see diagram.All these control logic make use of Struts-config.xml the document come to allocation.See diagr
23、am in the Struts frame main from JSP born page completion, the Struts provide abundant of JSP label database, this is advantageous to separating performance logic and procedure logic.The model is with 1 or the form existence of several Java Bean.In the Struts, main existence three kinds of Bean, res
24、pectively BE:Action, ActionForm, EJB perhaps Java Bean. The Struts frame have no concrete definition model layer of realization, in actually the development, model layer usually is close with business logic connect with each other, and want to carry on operation to the first floor data.The underneat
25、hs introduction is a kind of development strategy, lead the Hibernate into the model layer of Struts frame, usage it to carry on a data to pack with reflect to shoot, provide hold out for long time turn of support. 4 usage Hibernate and the Struts development J2 EE application 4.1 system structure diagram 3
