Java design Pattern--Singleton mode

A hungry man single-case mode:

 Package Com.design.singleton;  Public class Eagersingleton {    privatestaticfinalnew  Eagersingleton ();     Private  Eagersingleton () {}    publicstatic  Eagersingleton getinstance () {        return  Eager_singleton;    }}

When this class is loaded, the static variable Eager_singleton is initialized.

Lazy Single-Case:

 PackageCom.design.singleton; Public classLazysingleton {Private StaticLazysingleton Lazysingleton =NULL; PrivateLazysingleton () {} Public synchronized StaticLazysingleton getinstance () {if(Lazysingleton = =NULL){            return NewLazysingleton (); }        returnLazysingleton; }}

the "difference" a hungry man singleton mode instantiates itself when it is loaded. From the perspective of resource utilization, a hungry man is almost the same as the lazy. In terms of speed and reaction time, a hungry man is more than a lazy block. Lazy in the instantiation of the time, need to deal with multi-threaded problems.

There's a lot more to use.

Static internal class Single example:

 PackageCom.design.singleton; Public classInnersingleton {PrivateInnersingleton () {}Private Static classinner{Private StaticInnersingleton Instance =NewInnersingleton (); }     Public StaticInnersingleton getinstance () {returninner.instance; }         Public voiddosomething () {//Do something    }    }

This single thread-safe

Java design Pattern--Singleton mode