Java 简单类和数据的映射

#此代码包含：

1.一对一的映射

2.一对多的映射

3.多对多的映射

 

 

package yingshe;public class book { private String bookid; private String bookname; private String bookauthor; private double bookprice; private String bookpress; //出版社 private String bookkind; //类别 private Owners owner; //拥有者 private book[] books; private Owners[] owners;public Owners[] getOwners() {return owners;}public void setOwners(Owners[] owners) {this.owners = owners;}public book[] getBooks() {return books;}public void setBooks(book[] books) {this.books = books;}public Owners getOwner() {return owner;}public void setOwner(Owners owner) {this.owner = owner;}public book(String bookid,String bookname,String bookauthor,double bookprice,String bookpress,String bookkind) {// TODO Auto-generated constructor stubthis.bookid=bookid;this.bookname=bookname;this.bookauthor=bookauthor;this.bookprice=bookprice;this.bookpress=bookpress;this.bookkind=bookkind;}public String getBookid() {return bookid;}public void setBookid(String bookid) {this.bookid = bookid;}public String getBookname() {return bookname;}public void setBookname(String bookname) {this.bookname = bookname;}public String getBookauthor() {return bookauthor;}public void setBookauthor(String bookauthor) {this.bookauthor = bookauthor;}public double getBookprice() {return bookprice;}public void setBookprice(double bookprice) {this.bookprice = bookprice;}public String getBookpress() {return bookpress;}public void setBookpress(String bookpress) {this.bookpress = bookpress;}public String getBookkind() {return bookkind;}public void setBookkind(String bookkind) {this.bookkind = bookkind;}    public String getInfo(){    return "书的信息为：\n \t"+" id:"+this.bookid+", 书名："+this.bookname+" ,作者："+this.bookauthor+", 价格："+this.bookprice+" ,出版社："+this.bookpress+" ,类别："+this.bookkind;    }}package yingshe;public class Owners {private String ownerName;private String ownerId;private book book;private book [] books;private Owners [] owners;public Owners[] getOwners() {return owners;}public void setOwners(Owners[] owners) {this.owners = owners;}public book[] getBooks() {return books;}public void setBooks(book[] books) {this.books = books;}public Owners(String ownerName,String ownerId) {// TODO Auto-generated constructor stubthis.ownerName=ownerName;this.ownerId=ownerId;}public String getOwnerName() {return ownerName;}public void setOwnerName(String ownerName) {this.ownerName = ownerName;}public String getOwnerId() {return ownerId;}public void setOwnerId(String ownerId) {this.ownerId = ownerId;}public book getBook() {return book;}public void setBook(book book) {this.book = book;}public String getInfo(){return "拥有者的信息为：\n \t"+"拥有者的id："+this.ownerId+",拥有者的名字："+this.ownerName;}}package yingshe;public class bookDemo {public bookDemo() {// TODO Auto-generated constructor stub}public static void main(String[] args) {// TODO Auto-generated method stubbookDemo bookDemo=new bookDemo();System.out.println("一对一的映射：\n");//bookDemo.yiduiyi();System.out.println("一对多的映射：\n");//bookDemo.yiduiduo();System.out.println("多对多的映射：\n");bookDemo.duoduiduo();}public void yiduiyi(){book book=new book("001", "java核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");Owners owners=new Owners("王源", "9527"); //System.out.println(book.getInfo());//输出书的信息//System.out.println(owners.getInfo()); //输出拥有者的信息book.setOwner(owners); //设置书的拥有者owners.setBook(book); //设置拥有者的书System.out.println("通过书的拥有者 输出拥有者的信息：\n"+book.getOwner().getInfo()); //通过书的拥有者 输出拥有者的信息System.out.println("通过拥有者的书 输出书的信息：\n"+owners.getBook().getInfo());//通过拥有者的书 输出书的信息}public void yiduiduo(){book book=new book("001", "java核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book1=new book("002", "c核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book2=new book("003", "c++核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book books[]=new book[]{book,book1,book2}; //某人可能拥有这批书Owners owners=new Owners("王源", "9527"); owners.setBooks(books);//设置三本书拥有者book.setOwner(owners);book1.setOwner(owners);book2.setOwner(owners);System.out.println("通过拥有者找出他所拥有的书：");for(int i=0;i<owners.getBooks().length;i++){System.out.println();System.out.println(owners.getBooks()[i].getInfo());}System.out.println("通过书找出拥有者的信息：\n");for(int i=0;i<owners.getBooks().length;i++){System.out.println(books[i].getOwner().getInfo());}}public void duoduiduo(){//定义六本书book book=new book("001", "java核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book1=new book("002", "c核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book2=new book("003", "c++核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book3=new book("004", "c#核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book4=new book("005", "python核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book book5=new book("006", "linux核心技术", "沈雪冰", 69.8, "清华大学出版社","程序设计");book bookss []=new book[]{book,book1,book2,book3,book4,book5};book books[]=new book[]{book,book1,book2}; //某人可能拥有这批书book books1[]=new book[]{book3,book4};//某人可能拥有这批书book books2[]=new book[]{book2,book4};//某人可能拥有这批书//定义三个拥有者Owners owner=new Owners("王源", "9527"); Owners owner1=new Owners("李四", "9528");Owners owner2=new Owners("张三", "9529");Owners owners[]=new Owners[]{owner,owner1,owner2};Owners owners1[]=new Owners[]{owner};Owners owners2[]=new Owners[]{owner1,owner2};owner.setBooks(books); //owner拥有books这批书owner1.setBooks(books1);//owner1拥有books1这批书owner2.setBooks(books2);//owner2拥有books2这批书//设置每本书的多位拥有者book.setOwners(owners);book1.setOwners(owners);book2.setOwners(owners2);book3.setOwners(owners1);book4.setOwners(owners1); //book5.setOwners(owners2);System.out.println("通过书找到书的拥有者：\n");for(int i=0;i<bookss.length;i++){   try {if(bookss[i].getOwners()!=null)System.out.println(bookss[i].getInfo()+"\n 拥有者信息：\n"); for(int j=0;j<bookss[i].getOwners().length;j++)System.out.println(bookss[i].getOwners()[j].getInfo());} catch (Exception e) {// TODO: handle exceptionSystem.out.println(bookss[i].getInfo()+"\n还没有拥有者哦~！");} }System.out.println();System.out.println("通过拥有者找到书的信息：\n");for(int i=0;i<owners.length;i++){System.out.println(owners[i].getInfo()+"\n 拥有的书的信息：");for(int j=0;j<owners[i].getBooks().length;j++)System.out.println(owners[i].getBooks()[j].getInfo());}}}

 

 

 

一对一的映射结果：

一对多的映射结果：

多对多的映射结果：