This article compiles related documents from J2EE. MVC-View-Controller application structure is used to analyze the features of distributed applications. This abstract structure helps to divide applications into several logic components, making programming easier. The MVC structure provides a method for segmenting various objects in a function (these objects are used to maintain and perform data), and the purpose is to minimize coupling between each object. The MVC structure is originally designed to apply traditional input (INPUT), processing, output tasks to the graphical user interaction model. However, it is also also suitable for use in Web-based enterprise-based multi-layer applications. In the MVC structure, models (MODEL) represents the data (data) of the application and the business rules used to control access and modify this data. The usual model is used as a software that is approximately a process in the real world. When defining a model, a general simple modeling technique can be employed. When the model changes, it will notify the view (view) and the ability to provide the relevant status of the query model. At the same time, it also provides the ability to access the application functionality inside the model (Controller). A view (view) is used to organize the contents of the model. It gets data from the model and specifies how these data is manifested. When the model changes, it is responsible for maintaining the consistency of the data performance. Apply the user to inform the controller (Controller). Controller defines the behavior of the application; it is responsible for interpreting user requirements from the viewing and maps these requirements into corresponding behavior, which are implemented by the model. In standing GUI clients, user requirements may be some mouse click or menu selection operation. In a web application, their performance may be some HTTP requests from the client's GET or POST. The model implemented by the model includes the status of processing the business and modifying the model. Depending on the result of user requirements and model behavior, the controller selects a response to the user request. Typically a set of related functions set corresponding to a controller. The following figure depicts the relationship between the model, the three parts, the controller in the MVC application:
