Principle When implement the singleton pattern please decorate the INSTANCE field with "static final" and decorate the constructor with "private". // Singleton with static factory public class Elvis { private static final Elvis INSTANC…

ylbtech 原文 C#中的枚举类型(enum type) 概念 枚举类型(enum type)是具有一组命名常量的独特的值类型.在以下示例中: enum Color { Red, Green, Blue } 声明一个名为 Color 的枚举类型,该类型具有三个成员:Red.Green 和 Blue. 枚举具体是怎么声明呢?枚举声明用于声明新的枚举类型.枚举声明以关键字 enum 开始,然后定义该枚举类型的名称.可访问性.基础类型和成员.具体格式: 修饰词(new.public.protect…

原文网址:http://iaiai.iteye.com/blog/1843553 1   背景 在java语言中还没有引入枚举类型之前,表示枚举类型的常用模式是声明一组具有int常量.之前我们通常利用public final static 方法定义的代码如下,分别用1 表示春天,2表示夏天,3表示秋天,4表示冬天. public class Season { public static final int SPRING = 1; public static final int SUMMER = …

Item3:Enforce the singleton property with a private constructor or an enum type 采用枚举类型(ENUM)实现单例模式. public enum Elvis { INSTANCE; public void leaveTheBuiding(){ System.out.println("a single-element enum type is the best way to implement a singleton&q…

 1. 通过一个公开的字段来获取单例 // Singleton with public final field public class Elvis { public static final Elvis INSTANCE = new Elvis(); private Elvis() { ... } public void leaveTheBuilding() { ... } } The main advantage of the public field approach is that th…

1. Bean @Entity @Table(name = "entities") public class Entities { public enum entityType { location, group; } private entityType locationOrGroup; @Column(name="location_or_group") @Enumerated(EnumType.STRING) //Should set the type of l…

class Program { public enum TimeOfDay { Morining, Afternoon, Evening } static void Main(string[] args) { Console.WriteLine(TimeOfDay.Afternoon); } } Console.WriteLine(TimeOfDay.Afternoon);//Afternoon TimeOfDay TIME = TimeOfDay.Afternoon; Console.Writ…

 C++ Code  123   // Import the ADO type library #import "C:\\Program Files\\Common Files\\system\\ado\\msadox.dll"   #import "C:\\Program Files\\Common Files\\System\\ado\\msado15.dll" no_namespace rename ("EOF","adoEOF&…

作者:朱金灿 来源:http://blog.csdn.net/clever101 使用ado来连接数据库,结果出现这样一些编译错误: 1>f:\c++pro\iocptser\debug\msado15.tlh(228) : error C2011: "LockTypeEnum": "enum"类型重定义 1> c:\program files\microsoftsdks\windows\v6.0a\include\dbdaoint.h(109): 参见…

You can convert to an enum value from its underlying type by casting the underlying type (e.g. int) to the enum type. However, when you cast a value that doesn't have a corresponding enumerator in the type, you don't get any sort of error. In the exa…