JAVA中MVC写BMI

MVC（Model-View-Controller）是一种设计模式，用于将应用程序的不同方面分离开来，以便更好地进行维护和扩展。在Java中，可以使用MVC模式来编写BMI计算器。

1. Model（模型）：负责计算BMI值。

public class BMICalculator {
    private double height;
    private double weight;

    public void setHeight(double height) {
        this.height = height;
    }

    public void setWeight(double weight) {
        this.weight = weight;
    }

    public double calculateBMI() {
        return weight / (height * height);
    }
}

2. View（视图）：负责显示界面和接收用户输入。

import java.util.Scanner;

public class BMIView {
    private Scanner scanner;

    public BMIView() {
        scanner = new Scanner(System.in);
    }

    public void displayBMI(double bmi) {
        System.out.println("Your BMI is " + bmi);
    }

    public double getHeight() {
        System.out.print("Enter your height in meters: ");
        return scanner.nextDouble();
    }

    public double getWeight() {
        System.out.print("Enter your weight in kilograms: ");
        return scanner.nextDouble();
    }
}

3. Controller（控制器）：负责协调Model和View。

public class BMIController {
    private BMICalculator model;
    private BMIView view;

    public BMIController(BMICalculator model, BMIView view) {
        this.model = model;
        this.view = view;
    }

    public void calculateBMI() {
        double height = view.getHeight();
        double weight = view.getWeight();

        model.setHeight(height);
        model.setWeight(weight);

        double bmi = model.calculateBMI();

        view.displayBMI(bmi);
    }
}

在主函数中，创建Model、View和Controller，并调用Controller的calculateBMI方法。

public class Main {
    public static void main(String[] args) {
        BMICalculator model = new BMICalculator();
        BMIView view = new BMIView();
        BMIController controller = new BMIController(model, view);

        controller.calculateBMI();
    }
}