2016年1月18日 19:07:22人与书的类

描述一个人拥有一本书

一本书属于一个人

class Person{

private String name;

private int age;

private Book book;

public Person(String n,int a){

this.setName(n);

this.setAge(a);

}

public void setName(String n){

name=n;

}

public void setAge(int a){

age=a;

}

public void setBook(Book b){

book=b;

}

public String getName(){

return name;

}

public int getAge(){

return age;

}

public Book getBook(){

return book;

}

}

class Book{

private String title;

private float price;

private Person person;

public Book(String t,float pr){

this.setTitle(t);

this.setPrice(pr);

}

public void setTitle(String t){

title=t;

}

public void setPrice(float pr){

price=pr;

}

public void setPerson(Person p){

person=p;

}

public String getTitle(){

return title;

}

public float getPrice(){

return price;

}

public Person getPerson(){

return person;

}

}

public class RefDemo04 {

public static void main(String args[]){

Person ps=new Person("张三",30);

Book bk=new Book("java",80.0f);

ps.setBook(bk);

bk.setPerson(ps);

System.out.println(ps.getBook().getTitle());

System.out.println(bk.getPerson().getName());

}

}

运行结果：

java

张三

人有了一个孩子

package com.mz;

class Person2{

private String name;

private int age;

private Person2 child;

private Book2 book;

public Person2(String n,int a){

this.setName(n);

this.setAge(a);

}

public void setName(String n){

name=n;

}

public void setAge(int a){

age=a;

}

public void setChild(Person2 c){

child=c;

}

public void setBook(Book2 b){

book=b;

}

public String getName(){

return name;

}

public int getAge(){

return age;

}

public Person2 getChild(){

return child;

}

public Book2 getBook(){

return book;

}

}

class Book2{

private String title;

private float price;

private Person2 person;

public Book2(String t,float pr){

this.setTitle(t);

this.setPrice(pr);

}

public void setTitle(String t){

title=t;

}

public void setPrice(float pr){

price=pr;

}

public void setPerson(Person2 p){

person=p;

}

public String getTitle(){

return title;

}

public float getPrice(){

return price;

}

public Person2 getPerson(){

return person;

}

}

public class RefDemo05 {

public static void main(String args[]){

Person2 ps=new Person2("张三",30);

Book2 bk=new Book2("java",80.0f);

Person2 chd=new Person2("张四",10);

Book2 bkc=new Book2("童话",20.0f);

ps.setChild(chd);//人的孩子

chd.setBook(bkc);//孩子的书

bkc.setPerson(chd);//孩子的书属于孩子

ps.setBook(bk);//人的书

bk.setPerson(ps);//书属于一个人

System.out.println(ps.getBook().getTitle());

System.out.println(bk.getPerson().getName());

System.out.println(ps.getChild().getBook().getTitle());

System.out.println(chd.getName());

}

}