Detailed explanation of the technical principles and core concepts of the POJO MVCC framework in the Java class library

POJO MVCC framework technical principles and core concepts in the Java class library I. Introduction In the process of using Java for development, we often encounter the mapping relationship between the physical class (POJO) and the database data.In order to simplify the development process and improve the maintenance of code, we can use the MVCC (Model-View-Controller-Controller) framework.This article will introduce the technical principles and core concepts of the POJO MVCC framework in the Java library in detail. 2. Technical principles The core technology of the POJO MVCC framework is based on the observer mode and data binding mechanism.Below we will introduce these two technical principles in detail. 1. Observer mode Observer mode is a commonly used design pattern that defines a pair of multi -dependencies between objects. When the state of an object changes, the objects that rely on it will be notified and automatically updated.In the POJO MVCC framework, the physical class (POJO) acts as an observer, and the changes in the database data act as an observer, realizing the automatic synchronization between the physical class and the database data. 2. Data binding mechanism Data binding refers to the binding of the data model and UI elements together. When the data model changes, the UI element is also automatically updated.In the POJO MVCC framework, the data binding mechanism allows us to define the listener on the attributes of the physical class. When the attribute value changes, the trigger the monitor will automatically synchronize the change to the database, so as to realize the two -way physical and database data data.Bind. 3. Core concept In the POJO MVCC framework, there are some core concepts that need to be understood and mastered.Below we will introduce these core concepts in detail. 1. Pojo (POJO) The physical class refers to the Java class representing a table in the database, which corresponds to columns in the database.In the POJO MVCC framework, the physical class acts as the role of a data model and is responsible for storing and managing data. 2. Data model Data model refers to the represented by the physical class in the memory. Through the data model, we can operate and control the physical class.In the POJO MVCC framework, the data model assumes a mapping relationship between the physical class and the database data. 3. Database manager The database manager is one of the core components of the POJO MVCC framework. It is responsible for managing database connections, transaction processing and query operations.Through the database manager, we can easily perform database operations. 4. View (view) View refers to the user interface (UI), which is responsible for displaying the attribute value of the physical class.In the POJO MVCC framework, the view is bound by the data binding mechanism to the data model. When the data model changes, the view will be automatically updated. 5. Controller (Controller) The controller refers to a component that handles user interaction and business logic.In the POJO MVCC framework, the controller is responsible for receiving the user's input, updating the data model, and displaying changes in the data model through a view to the user. Code example: The following is a simple example that demonstrates the process of using the POJO MVCC framework: // The entity class (user.java) public class User { private String name; private int age; public User(String name, int age) { this.name = name; this.age = age; } // ... // Use the data binding mechanism to monitor the change of the name attribute public void setName(String name) { this.name = name; // Update the name field in the database DatabaseManager.getInstance().update("user", "name", name); } // Use the data binding mechanism to monitor the Age attribute change public void setAge(int age) { this.age = age; // Update the Age field in the database DatabaseManager.getInstance().update("user", "age", age); } // ... } // Controller (UserController.java) public class UserController { private User user; public UserController(User user) { this.user = user; } // Trigger this method when the user enters the name public void onNameChanged(String newName) { user.setName(newName); } // Trigger this method when the user enters the age public void onAgeChanged(int newAge) { user.setAge(newAge); } } // View (UserView.java) public class UserView { private User user; private UserController controller; public UserView(User user, UserController controller) { this.user = user; this.controller = controller; } public void showUserDetails() { // Show the user's name and age System.out.println("Name: " + user.getName()); System.out.println("Age: " + user.getAge()); } public void updateName(String newName) { // Update the data model when the user enters the name controller.onNameChanged(newName); } public void updateAge(int newAge) { // Update the data model when the user enters the age controller.onAgeChanged(newAge); } } // Main Program (Main.java) public class Main { public static void main(String[] args) { User user = new User("Alice", 25); UserController controller = new UserController(user); UserView view = new UserView(user, controller); view.showUserDetails(); // Users enter the new name and age view.updateName("Bob"); view.updateAge(30); view.showUserDetails(); } } The above example demonstrates the basic use process of the POJO MVCC framework. Through the physical listener and data binding mechanism of the physical class, the simultaneous update of the physical class and the database data and the update of the UI display.This design model simplifies the development process and improves the maintenance of the code. Fourth, summary This article details the technical principles and core concepts of the POJO MVCC framework in the Java library.Through the observer mode and data binding mechanism, the two -way synchronization between the physical class and the database data is realized, and the interaction operation of the user interface and the data model is completed through the interaction between the controller and the interview.Through the POJO MVCC framework, we can improve the maintenance and scalability of the code and accelerate the development speed.It is hoped that this article will help readers understand and master the POJO MVCC framework.