Java 3 single-instance mode

1. A Hungry man type

1  Packagesingleinstance;2 /**a hungry man, class loading creates instances, wastes resources, threads are safe*/3  Public classSINGLEDOME01 {4     //private construction methods to prevent direct new objects5     PrivateSingleDome01 () {6     }7     //when the class loads, the object is created8     Private StaticSingleDome01 instance =NewSingleDome01 ();9     //provides getter for easy access to private objectsTen      One      Public StaticSingleDome01 getinstance () { A         returninstance; -     } -}

2. Lazy Type

1  Packagesingleinstance;2 /**lazy-type, when called to instantiate, save resources, high concurrency thread is not secure*/3  Public classSINGLEDOME02 {4     //private construction methods to prevent direct new objects5     PrivateSingleDome02 () {6     }7     Private StaticSINGLEDOME02 instance;8     //provides getter for external calls to private objects, returning SINGLEDOME02 objects9      Public StaticSingleDome02 getinstance () {Ten         if(instance==NULL){ OneInstance =NewSingleDome02 (); A         } -         returninstance; -     } the}

Java 3 single-instance mode