關(guān)于接口隔離原則的一個(gè)實(shí)現(xiàn):
使用場(chǎng)合,提供調(diào)用者需要的方法,屏蔽不需要的方法.滿足接口隔離原則.
比如說(shuō)電子商務(wù)的系統(tǒng),有訂單這個(gè)類,有三個(gè)地方會(huì)使用到,
一個(gè)是門戶,只能有查詢方法,
一個(gè)是外部系統(tǒng),有添加訂單的方法,
一個(gè)是管理后臺(tái),添加刪除修改查詢都要用到.
根據(jù)接口隔離原則(ISP),一個(gè)類對(duì)另外一個(gè)類的以來(lái)性應(yīng)當(dāng)是建立在最小的接口上.
也就是說(shuō),對(duì)于門戶,它只能依賴有一個(gè)查詢方法的接口.
UML結(jié)構(gòu)如下:
下面是實(shí)現(xiàn)的代碼.
//--這兒不用接口繼承,因?yàn)榭赡艹霈F(xiàn)修改了父接口影響了子接口
interface IOrderForPortal{
String getOrder();
}
interface IOrderForOtherSys{
String insertOrder();
String getOrder();
}
interface IOrderForAdmin{ //extends IOrderForPortal,IOrderForOtherSys
String deleteOrder();
String updateOrder();
String insertOrder();
String getOrder();
}
/*
interface IOrderForPortal{
String getOrder();
}
interface IOrderForOtherSys{
String insertOrder();
}
interface IOrderForAdmin extends IOrderForPortal,IOrderForOtherSys{
String updateOrder();
String deleteOrder();
}
*/
class Order implements IOrderForPortal,IOrderForOtherSys,IOrderForAdmin{
private Order(){
//--什么都不干,就是為了不讓直接 new,防止客戶端直接New,然后訪問(wèn)它不需要的方法.
}
//返回給Portal
public static IOrderForPortal getOrderForPortal(){
return (IOrderForPortal)new Order();
}
//返回給OtherSys
public static IOrderForOtherSys getOrderForOtherSys(){
return (IOrderForOtherSys)new Order();
}
//返回給Admin
public static IOrderForAdmin getOrderForAdmin(){
return (IOrderForAdmin)new Order();
}
//--下面是接口方法的實(shí)現(xiàn).只是返回了一個(gè)String用于演示---------------
public String getOrder(){
return "implemented getOrder";
}
public String insertOrder(){
return "implemented insertOrder";
}
public String updateOrder(){
return "implemented updateOrder";
}
public String deleteOrder(){
return "implemented deleteOrder";
}
}
public class TestCreateLimit{
public static void main(String[] args){
IOrderForPortal orderForPortal = Order.getOrderForPortal();
IOrderForOtherSys orderForOtherSys = Order.getOrderForOtherSys();
IOrderForAdmin orderForAdmin = Order.getOrderForAdmin();
System.out.println("Portal門戶調(diào)用方法:"+orderForPortal.getOrder());
System.out.println("OtherSys外部系統(tǒng)調(diào)用方法:"+orderForOtherSys.insertOrder());
System.out.println("Admin管理后臺(tái)調(diào)用方法:"+orderForAdmin.getOrder()+";"+orderForAdmin.insertOrder()+";"+orderForAdmin.updateOrder()+";"+orderForAdmin.deleteOrder());
}
}
這樣就能很好的滿足接口隔離原則了,調(diào)用者只能訪問(wèn)它自己的方法,不能訪問(wèn)到不應(yīng)該訪問(wèn)的方法.
歡迎討論...寫(xiě)這些的目的就是為了共同進(jìn)步,有什么錯(cuò)誤或者不足,歡迎指出....