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java - 单个和多个对象的 MVC 模式的实现

问题描述

我已经使用 MVC 模式（教程：链接）实现了学生管理。我决定将学生分为“SingleStudentModel”和“MultipleStudentModel”，但我不确定这对我来说是否有意义。总的来说，我对我的解决方案不满意。是否可以使用一个控制器处理单个学生和多个学生？如果模型导入到视图类中可以吗（参见StudentView.java）？

我该如何改进这个项目？

提前致谢。

Student.java（模型，数据类（？））

public class Student {

    private String name;
    private int nr;

    public Student(String _name, int _nr){
        this.name = _name;
        this.nr = _nr;
    }

    // get set
}

SingleStudentModel.java（模型）

public class SingleStudentModel {
    private Student student;

    // get set
}

StudentController.java (控制器 -> SingleStudentModel)

public class StudentController {
    private SingleStudentModel model;
    private StudentView view;

    public StudentController(SingleStudentModel _model, StudentView _view){
        this.model = _model;
        this.view = _view;
    }

   // set get

    public void updateView(){
        view.printStudentDetails(model.getStudent().getName(), model.getStudent().getNr());
    }
}

MultipleStudentModel.java（模型）

public class MultipleStudentModel {
    private Collection<Student> students = new ArrayList<Student>();

    public Collection<Student> getStudents() {
        return students;
    }

    public void setStudents(Student student){
        this.students.add(student);
    }
}

StudentsController.java (控制器 -> StudentsModel)

public class StudentsController {
    private MultipleStudentModel model;
    private StudentsView view;

    public StudentsController(MultipleStudentModel _model, StudentsView _view){
        this.model = _model;
        this.view = _view;
    }

    public void updateView(){
        view.printStudentList(model.getStudents());
    }
}

StudentView.java

public class StudentView {
    public void printStudentDetails(String _name, int _nr){
        System.out.println("Student: ");
        System.out.println("name: " + _name);
        System.out.println("nr: " + _nr);
    }
}

学生视图.java

import com.mvc.model.Student;

import java.util.Collection;

public class StudentsView {

    public void printStudentList(Collection<Student> students){

        System.out.println("\nStudent list");

        for(Student item : students){
            System.out.println("name: " + item.getName());
            System.out.println("nr: " + item.getNr());
        }
    }
}

主.java

 public class Main {

       public static void main(String [] args){

            //Single student
            SingleStudentModel model = new SingleStudentModel();
            StudentView view = new StudentView();
            StudentController controller = new StudentController(model, view);

            model.setStudent(new Student("John", 1));

            controller.updateView();

            //Multiple student
            MultipleStudentModel model2 = new MultipleStudentModel();
            StudentsView view2 = new StudentsView();
            StudentsController controller2 = new StudentsController(model2, view2);

            model2.setStudents(new Student("Zelda", 2));
            model2.setStudents(new Student("Link", 3));

            controller2.updateView();

            }
      }

标签： javadesign-patternsmodel-view-controller

解决方案

您可以创建model两个类的接口MultipleStudentModel并将SingleStudentModel实现

所以你不需要定义两个基本共享相同逻辑的控制器，这也可以让你在运行时更改控制器行为setModel

这还将创建一个合同，将您的模型绑定到特定方法，如 get 等（插入/更新/删除）

public class StudentController {
    private Model model;
    private StudentView view;

    public StudentController(Model _model, StudentView _view){
        this.model = _model;
        this.view = _view;
    }

    public setModel(Model model){
         this.model = model;
    }


}

你也可以在View课堂上做到这一点

另外，基本上一个学生只是一个学生列表，只包含一个元素，你可以删除冗余

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