Question

我很难理解如何使用来自两个不同类的具有相同名称的多个方法（在这种情况下，是两个相同的方法）。驱动程序类（计算机）正在使用Model和Laptop类来显示来自用户输入的信息。在“模型”和“便携式计算机”中，有两种名称相同但参数不同的方法。我对在笔记本电脑中为setModel方法设置三个参考变量的设置感到困惑。我曾尝试为setModel方法处理模型对象，但未成功。

我正在从UML图编写。笔记本电脑和型号之间存在聚合关系，特别是型号HAS-A与笔记本电脑的关系（笔记本电脑上有一条菱形，通过一条线连接到型号）。

import java.util.*;

public class Computer
 {
  public static void main (String[] args)
   {
       // local variables, can be accessed anywhere from the main method
       char input1 = 'Z';
       String inputInfo;
       String brandName, modelName;
       double price, cpuSpeed;
       int ramSize;

       String line = new String();

       // instantiate a Laptop object
       Laptop laptop1 = new Laptop();

       printMenu();

       //Create a Scanner object to read user input
       Scanner scan = new Scanner(System.in);

       do  // will ask for user input
        {
         System.out.print("What action would you like to perform?\n");
         line = scan.nextLine();

         if (line.length() == 1)
          {
           input1 = line.charAt(0);
           input1 = Character.toUpperCase(input1);

           // matches one of the case statement
           switch (input1)
            {
             case 'A':   //Add the laptop
               System.out.print("Please enter the laptop information:\n");
               System.out.print("What is the laptop\'s brand?\n");
               brandName = scan.nextLine();
               laptop1.setBrand(brandName);

               System.out.print("What is the laptop\'s model?\n");
               modelName = scan.nextLine();

               System.out.print("What is the laptop\'s CPU speed(in GHz)?\n");
               cpuSpeed = Double.parseDouble(scan.nextLine());

               System.out.print("What is the laptop\'s RAM size(in GB)?\n");
               ramSize = Integer.parseInt(scan.nextLine());

               laptop1.setModel(modelName, cpuSpeed, ramSize);

               System.out.print("How much is the laptop\'s price?\n");
               //price = scan.nextDouble();
               price = Double.parseDouble(scan.nextLine());
               laptop1.setPrice(price);

               break;
             case 'D':   //Display Pet
               System.out.print(laptop1);
               break;
             case 'Q':   //Quit
               break;
             case '?':   //Display Menu
               printMenu();
               break;
             default:
               System.out.print("Unknown action\n");
               break;
            }
          }
         else
          {
           System.out.print("Unknown action\n");
          }
        } while (input1 != 'Q' || line.length() != 1);
   }

  /** The method printMenu displays the menu to a user **/
  public static void printMenu()
   {
     System.out.print("Choice\t\tAction\n" +
                        "------\t\t------\n" +
                        "A\t\tAdd a Laptop\n" +
                        "D\t\tDisplay the Laptop\n" +
                        "Q\t\tQuit\n" +
                        "?\t\tDisplay Help\n\n");
  }

}

import java.text.NumberFormat;
import java.util.Locale;
public class Laptop {

    // TODO Auto-generated method stub
    private String BrandName;
    private Model model;
    private double price;


    public String getBrand()
    {
        return BrandName;
    }

    public Model getModel()
    {
        return model;
    }

    public double getPrice()
    {
        return price;
    }

    public void setBrand(String newBrand)
    {
        BrandName = newBrand;
    }

    public void setModel(String newModel, double newCPU, int newRAM)
    {


    }

    public void setPrice(double newPrice)
    {
        price = newPrice;
    }

    public String toString()
    {
        NumberFormat mf = NumberFormat.getCurrencyInstance(Locale.US);
        return ("\nBrand:\t" + BrandName + model.toString() +"\n" + "Price:\t " + mf.format(price) + "\n");
    }

}

import java.text.DecimalFormat;
public class Model {

private String modelName;
private double cpuSpeed;
private int ramSize;

    // TODO Auto-generated method stub
    public Model()
    {
        this.modelName = "?";
        this.cpuSpeed = 0.0;
        this.ramSize = 0;
    }

    public String getModel()
    {
        return modelName;
    }

    public double getCPU()
    {
        return cpuSpeed;
    }

    public int getRAM()
    {
        return ramSize;
    }

    public void setModel(String newModel)
    {
        modelName = newModel;
    }

    public void setCPU(double newCPU)
    {
        cpuSpeed = newCPU;
    }

    public void setRAM(int newRam)
    {
        ramSize = newRam;
    }

    public String toString()
    {
        DecimalFormat df = new DecimalFormat("0.00");
         return ("Model:\t" + modelName + "\n CPU:\t " + df.format(cpuSpeed) + "\n RAM:\t " + ramSize+"GB" + "\n" );
    }

}

Answer 1

如果方法是在不同的类中声明的，则甚至不需要其他参数，只需使用对象名称进行调用，然后自动调用响应方法ist。

Answer 2

这就是让我感到困惑的地方，我不会以这种方式实现它，但是我必须这样做。

我通过最初的实现找到了解决方案

public void setModel(String newModel, double newCPU, int newRAM)
    {
    model.setModel(newModel);
    model.setCPU(newCPU);
    model.setRAM(newRAM);
    }

然后我修复了Model对象的实例

private Model model = new Model();

来自多个类的重写方法

2 个答案: