java - 将 ArrayList 分配给 Java 中的列表

Question

我正在实现可以考虑以下 junit 测试的代码:

package it.unica.pr2.pizze.test;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import static org.junit.Assert.assertTrue;

import org.junit.Test;
import org.junit.Ignore;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import java.util.*; 
import it.unica.pr2.pizze.*; 

@RunWith(JUnit4.class)
public class TestPizza {

  @Test
    public void test1() {
      Ingrediente mozzarella = new Ingrediente("mozzarella",50);
      Ingrediente pomodoro = new Ingrediente("pomodoro",10);
      Ingrediente[] ingredienti = new Ingrediente[] {mozzarella, pomodoro}
      Pizza pizzaMargherita = new Pizza(ingredienti);
      assertTrue( pizzaMargherita.calorie() == 60 );
      List ingredientiMargherita = pizzaMargherita;
        assertTrue(ingredientiMargherita.size() ==2);
        assertTrue(ingredientiMargherita.get(0) == mozzarella);
        assertTrue(ingredientiMargherita.get(1) == pomodoro);
     }

这是我的类(class):披萨

package it.unica.pr2.pizze;
import java.util.ArrayList;
import java.util.List;

public class Pizza  {


    private ArrayList<Ingrediente> ingredienti;


    public Pizza(Ingrediente[] ing) {

        this.ingredienti = new ArrayList<>();

        int i = 0;
        while (i < ing.length) {

            this.ingredienti.add(ing[i]);
            i++;
        }

    }

    public double calorie(){

        double sumaCalorie = 0;

        for(Ingrediente elem: this.ingredienti)
            sumaCalorie += elem.getCalorie();

        return sumaCalorie;

    }
}

还有一个类:Ingrediente

package it.unica.pr2.pizze;


public class Ingrediente  {


    private String nomeIngrediente;
    private double calorie;



    public Ingrediente(String nomeIngrediente, double calorie) throws IngredienteNonValidoException {

        this.nomeIngrediente = nomeIngrediente;
        if (calorie < 0) throw new IngredienteNonValidoException();
        else
            this.calorie = calorie;
    }

    public void setNomeIng(String nomeIngrediente) {
        this.nomeIngrediente = nomeIngrediente;
    }

    public void setCalorie(double calorie) {

        this.calorie = calorie;
    }

    public String getNomeIng() {

        return this.nomeIngrediente;
    }

    public double getCalorie() {
        return this.calorie;
    }

}

运行测试后出现如下错误:

错误:类型不兼容:无法将 Pizza 转换为 List

列出成分iMargherita = pizzaMargherita;

所以我不知道如何仅使用运算符=将ArrayList转换为List，我无法修改junit测试代码。

Answer 1

如果你不能修改作业，你必须这样做:

public class Pizza implements List {
...
}

或者类似的东西，比如

public class Pizza extends AbstractList {
...
}