java架构有哪些—java架构搭建：代码示例

Java架构搭建主要有以下几种常见的架构模式：MVC、MVP、MVVM和微服务架构。

1. MVC（Model-View-Controller）模式是一种将应用程序分为三个核心组件的架构模式。Model负责处理数据逻辑，View负责展示用户界面，Controller负责接收用户输入并进行处理。示例代码如下：

// Model
public class User {
    private String name;
    private int age;
    // getters and setters
}
// View
public class UserView {
    public void displayUserDetails(User user) {
        System.out.println("Name: " + user.getName());
        System.out.println("Age: " + user.getAge());
    }
}
// Controller
public class UserController {
    private User model;
    private UserView view;
    public UserController(User model, UserView view) {
        this.model = model;
        this.view = view;
    }
    public void updateUserDetails(String name, int age) {
        model.setName(name);
        model.setAge(age);
    }
    public void displayUserDetails() {
        view.displayUserDetails(model);
    }
}
// Usage
public class Main {
    public static void main(String[] args) {
        User user = new User();
        UserView view = new UserView();
        UserController controller = new UserController(user, view);
        controller.updateUserDetails("John", 25);
        controller.displayUserDetails();
    }
}

2. MVP（Model-View-Presenter）模式是在MVC模式的基础上演化而来，将Controller改为Presenter，更加关注业务逻辑的处理。示例代码如下：

// Model
public class User {
    private String name;
    private int age;
    // getters and setters
}
// View
public interface UserView {
    void displayUserDetails(User user);
}
// Presenter
public class UserPresenter {
    private User model;
    private UserView view;
    public UserPresenter(User model, UserView view) {
        this.model = model;
        this.view = view;
    }
    public void updateUserDetails(String name, int age) {
        model.setName(name);
        model.setAge(age);
    }
    public void displayUserDetails() {
        view.displayUserDetails(model);
    }
}
// Usage
public class Main {
    public static void main(String[] args) {
        User user = new User();
        UserView view = new UserView() {
            @Override
            public void displayUserDetails(User user) {
                System.out.println("Name: " + user.getName());
                System.out.println("Age: " + user.getAge());
            }
        };
        UserPresenter presenter = new UserPresenter(user, view);
        presenter.updateUserDetails("John", 25);
        presenter.displayUserDetails();
    }
}

3. MVVM（Model-View-ViewModel）模式是一种将View和Model之间的数据绑定交给ViewModel来处理的架构模式。示例代码如下：

// Model
public class User {
    private String name;
    private int age;
    // getters and setters
}
// View
public class UserView {
    private UserViewModel viewModel;
    public UserView(UserViewModel viewModel) {
        this.viewModel = viewModel;
    }
    public void displayUserDetails() {
        System.out.println("Name: " + viewModel.getName());
        System.out.println("Age: " + viewModel.getAge());
    }
}
// ViewModel
public class UserViewModel {
    private User model;
    public UserViewModel(User model) {
        this.model = model;
    }
    public String getName() {
        return model.getName();
    }
    public int getAge() {
        return model.getAge();
    }
}
// Usage
public class Main {
    public static void main(String[] args) {
        User user = new User();
        UserViewModel viewModel = new UserViewModel(user);
        UserView view = new UserView(viewModel);
        user.setName("John");
        user.setAge(25);
        view.displayUserDetails();
    }
}

4. 微服务架构是一种将应用程序拆分为多个独立部署的小服务的架构模式。每个服务都有自己的独立数据库和业务逻辑，通过API进行通信。示例代码如下：

// UserService
public class UserService {
    public User getUserById(int id) {
        // retrieve user from database
    }
    public void saveUser(User user) {
        // save user to database
    }
    public void deleteUser(int id) {
        // delete user from database
    }
}
// OrderService
public class OrderService {
    public Order getOrderById(int id) {
        // retrieve order from database
    }
    public void saveOrder(Order order) {
        // save order to database
    }
    public void deleteOrder(int id) {
        // delete order from database
    }
}
// Usage
public class Main {
    public static void main(String[] args) {
        UserService userService = new UserService();
        User user = userService.getUserById(1);
        OrderService orderService = new OrderService();
        Order order = orderService.getOrderById(1);
        // perform business logic with user and order
    }
}

这些架构模式在实际开发中根据项目的需求和规模选择合适的架构，可以提高代码的可维护性、可扩展性和可测试性。