java设计设计一个书包类（SchoolBag）及行李包类(Luggage)，书包只能放书（Book），

java设计设计一个书包类（SchoolBag）及行李包类(Luggage)，书包只能放书（Book），

图 呢追答大致结构
package bagstuff.bag;

import bagstuff.stuff.Stuff;

import java.util.ArrayList;
import java.util.List;


public class Bag {
    private List stuffs = new ArrayList();

    public void putStuff(Stuff stuff) {
        stuffs.add(stuff);
        System.out.println("包里面放进了一个东西：" + stuff);
    }

    public void getStuff() {
        for (Stuff stuff : stuffs) {
            System.out.println("从包里面拿出了一个东西：" + stuff);
        }
    }
}
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package bagstuff.bag;

import bagstuff.stuff.Cloth;


public class Luggage extends Bag {
    //只能放衣服
    public void putCloth(Cloth cloth) {
        super.putStuff(cloth);
    }
}

--------------------------
package bagstuff.bag;

import bagstuff.stuff.Book;


public class SchoolBag extends Bag {
    //只能放数
    public void putCloth(Book book) {
        super.putStuff(book);
    }
}package bagstuff.stuff;public class Book extends Stuff { private Long wordsNumber; public Book(String name) { super(name); } public Long getWordsNumber() { return wordsNumber; } public void setWordsNumber(Long wordsNumber) { this.wordsNumber = wordsNumber; }}------------------------package bagstuff.stuff;public class Cloth extends Stuff { private Integer level; public Cloth(String name) { super(name); } public Integer getLevel() { return level; } public void setLevel(Integer level) { this.level = level; }}-------------------------package bagstuff.stuff;public class Stuff { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public Stuff(String name) { this.name = name; } @Override public String toString() { return "Stuff{" + "name='" + name + '\'' + '}'; }}--------------------------------​package bagstuff;import bagstuff.bag.Bag;import bagstuff.bag.Luggage;import bagstuff.bag.SchoolBag;import bagstuff.stuff.Book;import bagstuff.stuff.Clot--------------------------------​package bagstuff;import bagstuff.bag.Bag;import bagstuff.bag.Luggage;import bagstuff.bag.SchoolBag;import bagstuff.stuff.Book;import bagstuff.stuff.Cloth;import bagstuff.stuff.Stuff;public class MainTest { public static void main(String[] args) { // 1)创建Stuff数组 Stuff[] stuffs = new Stuff[20]; Bag schoolBag = new SchoolBag(); Bag luggage = new Luggage(); for (int i = 0; i < 9; i++) { stuffs[i] = new Book("第" + (i + 1) + "本书"); //2)书包putStuff操作 schoolBag.putStuff(stuffs[i]); } //书包getStuff操作 schoolBag.getStuff(); for (int i = 9; i < 20; i++) { stuffs[i] = new Cloth("第" + (i + 1) + "件衣服"); //2)行李包putStuff操作 luggage.putStuff(stuffs[i]); } //行李包getStuff操作 luggage.getStuff(); //3)输出所有stuff for (Stuff stuff : stuffs) { System.out.println(stuff); } }}