Common design patterns [Singleton mode]

A similar problem occurs: the generation of production numbers, the ticketing system, and other data need to be synchronized. Think of the singleton mode immediately ....

ExampleCode:

 
Package Singleton;/*** @ description: singleton mode * @ author Potter * @ date 10:08:16 * @ version V1.0 */public class app {public static void main (string [] ARGs) {numdevice G = numdevice. getinstance (); // greedy2 G = greedy2.instance; system. out. println (G. next (); show ();} public static void show () {numdevice G = numdevice. getinstance (); // numdevice2 G = numdevice2.instance; system. out. println (G. next ());}}
 

Method 1: implement with classes:

 
Package Singleton;/*** @ description: singleton class * @ author Potter * @ date 10:01:45 * @ version V1.0 */public class numdevice {private final static numdevice me = new numdevice (); Private numdevice () {} public static numdevice getinstance () {return me;} private int count; Public int next () {return count ++ ;}}
 

Method 2: Use enumeration classes

 
Package Singleton;/*** @ Description: Singleton class * @ author Potter * @ date 10:01:45 * @ version V1.0 */Public Enum numdevice2 {instance; private int count; public int next () {return count ++ ;}}