人事管理信息系统外文文献及翻译(5页).doc

-人事管理信息系统外文文献及翻译-第 - 5 - 页MVC Design PatternMVC is a widely popular software design pattern, as early as in the 70's, IBM introduced the Sanfronscisico on the project, in fact, is the MVC design pattern research. Recently, with the maturity of J2EE, it is becoming a recommendation in the J2EE platform, a design model, the majority of Java developers are also very interested in the design model. MVC model is gradually developed in PHP and ColdFusion are in use, and growth trends. With the rapid increase in web applications, MVC model for the development of Web applications is a very advanced design idea, no matter what language you choose, no matter how complicated the application, it can be for you to understand and provide the most basic application model analytical methods, structural products for you to provide a clear framework for the design, for your software projects in accordance with norms.MVC design ideaMVC in English or Model-View-Controller, an application that is input, process, output process in accordance with the Model, View, Controller isolated manner, such an application is divided into three layers - model layer, view layer, control layer.View (View) on behalf of the user interface for Web applications can be summed up as HTML interface, but has the potential to XHTML, XML, and Applet. With the application of the complexity and scale, the interface has become challenging to deal with. An application may have different views, MVC design pattern to deal with the view of the limited view of data acquisition and processing, as well as the user's request, not included in the view on the handling of business processes. The handling of business processes to the model (Model) to deal with. For example, a view only accept orders from the model data and display to users, as well as input user interface data and the request passed to the control and model.Model (Model): is the business process / status of the processing and business rules. Business process layer is the other black-box operation, the model view to accept the request of the data, and return the results of the final. The design of business models can be said to be the most important core of MVC. Currently popular model of EJB applications is a typical example of the application of technology from the perspective of the model further delineation in order to make full use of existing components, but it can not be used as a framework for application design model. It only tell you that according to the design of this model will be able to use certain technology components, thereby reducing the technical difficulties. Example of a developer, you can focus on business model design. MVC design pattern tells us that the application of the model according to certain rules of taking away the level of extraction is very important, which is to determine whether the development in accordance with good design. Abstract and concrete can not be separated too far, nor too close.MVC model did not provide the design method, but only tell you that the management of these models should be organized in order to facilitate reconstruction and improve the model reusability. We can make an analogy with object programming, MVC defines a top-level category, the sub-class to tell it you have to do these, but you can not do these restrictions. This is the developer of the programming is very important.There is also a business model of the model is very important that the data model. Data model mainly refers to the object data entities (continued of).Forexample, an order will be saved to the database, to obtain orders from the database. We can separate this model, all the operation of the database is only.limited to the model.Control (Controller) can be interpreted as a request received from the user, matching the model and view together to complete the user's request. The role of division of control layer is also very clear that it clearly tell you that it is a distributed, and what kind of model to choose, choose what kind of view, to complete what the user requests. Control layer does not do any data processing. For example, the user clicks on a link and control layer to receive arequest, does not deal with business information, only the user's information to the model, to tell what model to choose the view to meet the requirements to return to the user. Therefore, a model may correspond to multiple views, one view may correspond to a number of models.The benefits of MVCMost of the process of language use such as ASP, PHP developed Web applications, the development of the initial template is the mixed layer of the data programming. For example, send the request directly to the database and display HTML, development speed is often faster, but because of the separation of data pages is not very direct, and therefore reflect the business model difficult to look or model reusability. Very flexible product design efforts, it is difficult to meet the changing needs of users. MVC layered on the application of the requirements, although additional work would take, but clearly the structure of products, product application through the model can be better reflected.First of all, the most important thing is that there should be a number of view corresponds to the ability of a model. In the current rapidly changing user requirements, it may have access to awide range of applications. For example, orders for the model may be orders of the system as well as online orders, or orders for other systems, but the handling of orders is the same, that is to say the handling of orders is the same. MVC design pattern in accordance with a orders for models and multiple views can solve the problem. This reduced the code to copy, that is, a reduction of the maintenance code, once the model changes, but also easy to maintain.MVC Design ModelSecondly, the data returned as a result of the model without any display format, so these models can also be directly applied to the use of interfaces.Third, as a result of an application to be separated into three, it is sometimes one of them will be able to change to meet changes in the application.An application of business processes or business rules change simply changes the model layer MVC.The concept of control layer is also very effective, because of its different models and different views together to complete various requests, the control layer can be said to be included in the concept of a user request for permission.Finally, it is also beneficial to the management of software engineering. Because each different layer, each layer of different applications have some similar characteristics, is conducive to the adoption of engineering and management tools of program code generated.The shortcomings of MVCDesign and implementation of MVC is not very easy, easier to understand, but for developers the requirements are relatively high. MVC is just a basic designidea, but also the need for careful design and planning.Model and the strict separation of view may make debugging more difficult, but easier to find errors.Experience has shown that, MVC as a result of the application is divided into three, means that the number of code files, so the need for document management.costs point thought.Above, MVC is a very good software to build a basic model, at least the separation of processing and display, forcing the application is divided into model, view and control layer, making you seriously consider the additional complexity of the application of these ideas into the structure, an increase of application scalability. If we can grasp this, MVC model will make your application stronger, more flexible and more personalized.指导教师评语： 签名： 年 月 日