Java Singleton mode &static member variable differences

When there are many variables that need to be shared, it takes too long to use a static variable for the entire life cycle of the class. The object is only present in the entire life cycle of the object.

// a hungry man type class Single// class once loaded, the object already exists.  {privatestaticnewprivatepublic  static single getinstance () {return  s;}}

//Lazy TypeclassSingle2//class is loaded, there are no objects, and only objects are created when the GetInstance method is called. //deferred loading form. There is a security risk in the concurrency process. {Private StaticSingle2 s =NULL; PrivateSingle2 () {} Public StaticSingle2 getinstance () {if(s==NULL) s=NewSingle2 ();returns;}}

Java Singleton mode &static member variable differences