Java EE architecture and javaee Architecture

Java EE architecture and javaee Architecture

The Java EE architecture generally includes the following layers:

1. Domain Object Layer: This layer is mainly composed of abstract Object models (also known as POJO and Plain Old Java Object ), it generally includes the business logic methods required by each other. Generally, the statuses of these object models must be stored in the database to provide persistence support;

2. DAO (Database Access Object) layer: This layer is composed of a series of DAO components to complete CRUD (create, query retrieve, update, delete) operations on the Database;

3. Business logic layer: This layer is composed of a series of business logic objects that implement the logical methods required by the system, these business logic methods may only be used to expose the business logic methods implemented by the Domain Object, or the business logic methods implemented by DAO. For implementation;

4. Controller layer: This layer is mainly composed of controller components. The controller is used to intercept user requests and forward the requests to their corresponding business logic methods. It processes user requests, and forward the processing results to different presentation layer components;

5. Presentation Layer: This layer consists of a series of view components, including JSP pages and Velocity pages. This layer collects user requests and displays the processing results to users;

Java EE components are loosely coupled to each other. From top to bottom, the upper-layer components depend on the lower-layer components. from bottom to top, the lower-layer components provide support for the upper-layer components,