38.集合：Collection集合存储自定义类型的对象

Collection集合存储自定义类型的对象

• 案例：影片信息在程序中的表示

• 需求：某影院系统需要在后边存储上述三部电影，然后依次展示出来

• 分析：

  • 定义一个电影类，定义一个集合存储电影对象
  • 创建三个电影对象，封装相关数据，把三个对象存入到集合中去
  • 遍历集合中的3个对象，输出相关信息

• 测试代码

  package com.java.collection;
  
  public class Movie {
      private String name;
      private double score;
      private String actor;
  
      public Movie() {
      }
  
      public Movie(String name, double score, String actor) {
          this.name = name;
          this.score = score;
          this.actor = actor;
      }
  
      public String getName() {
          return name;
      }
  
      public void setName(String name) {
          this.name = name;
      }
  
      public double getScore() {
          return score;
      }
  
      public void setScore(double score) {
          this.score = score;
      }
  
      public String getActor() {
          return actor;
      }
  
      public void setActor(String actor) {
          this.actor = actor;
      }
  
      @Override
      public String toString() {
          return "Movie{" +
                  "name='" + name + '\'' +
                  ", score=" + score +
                  ", actor='" + actor + '\'' +
                  '}';
      }
  }
  
  

  package com.java.collection;
  
  import java.util.ArrayList;
  import java.util.Collection;
  
  public class MovieTestDemo {
      public static void main(String[] args) {
          Collection movies = new ArrayList<>();
          // 多态存在访问问题，左边的父类不能调用右边的子类方法
          // 因此不能使用for循环遍历Collection
  
          movies.add(new Movie("《头文字D》",9.8,"陈冠希"));  // 直接new出并代入，加进来的是地址
          movies.add(new Movie("《头文字D》",9.8,"张柏芝"));
          movies.add(new Movie("《武郎卖饼》",6.8,"谢霆锋"));
  
          System.out.println(movies); // 前提是Movie类重写toString()方法
  
          for (Movie movie : movies) {
              System.out.println("片名：" + movie.getName());
              System.out.println("评分：" + movie.getScore());
              System.out.println("主演：" + movie.getActor());
              System.out.println();
          }
  
      }
  }
  
  

• 集合中存储的是元素对象的地址