single responsibility principle單一職責原則
open close principle開閉原則
liskov substitution principle里氏替換原則
Low of Demete迪米特法則
interface segregation principle接口隔離原則
dependence inversion principle依賴倒置原則
SOLID
開閉原則：
public interface IBook{
public String getName();
public int getPrice();
public String getAuthor();
}
===================================================
小說書籍的源代碼如下：
public class NovelBook implements IBook{
private String name;
private int price;
private String author;
public NovelBook(String _name,int _price,String _author){
this.name=_name;
this.price=_price;
this.author=_author;
}
public String getAuthor(){
return this.author;}
public String getName(){
return this.name;}
public int getPrice(){
return this.price;}
}
}
========================================================
銷售書籍：
public class BookStore{
private final static ArrayList<IBook> bookList= new ArrayList<IBook>();
static{
bookList.add(new NovelBook("天龍八部1",3200,"金庸"))；
bookList.add(new NovelBook("天龍八部2",3200,"金庸"))；
bookList.add(new NovelBook("天龍八部3",3200,"金庸"))；
bookList.add(new NovelBook("天龍八部4",3200,"金庸"))；
}
public static void main(Sting() args){
NumberFormat formatter=NumberFormat2.getCurrencyInstance();
formatter.setMaximunFractionDigits(2);
System.out.println("--------------書店買出去的書籍如下")；
for(IBook book:bookList){
book.getName();
book.getAuthor();
book.getPrice();
}
}
}