A single-instance design pattern for Java design patterns

Java Singleton design pattern, there are many ways to implement, the following describes some of the more famous implementation methods

1. A Hungry man type

   This design pattern is simple, and there is no multi-threading security problem, which is generally used in practical development.

Class Hungerydemo{private Hungerydemo () {}private static final Hungerydemo instance = new Hungerydemo ();p ublic static Hung Erydemo getinstance () {return instance;}}

2. Lazy Type

This mode is delayed loading and is highly efficient.

This design pattern is more complex, there are multithreading security problems. You can use synchronous functions or synchronize blocks of code to avoid each

Determine the lock, use synchronous code block and double judge the way to solve the thread safety problem. Note that the lock should be a byte-code file for the class

Class Lazydemo{private Lazydemo () {}private static Lazydemo instance = Null;public static Lazydemo getinstance () {if ( Instance==null) {synchronized (Lazydemo.class) {if (instance==null) {instance = new Lazydemo ();}}} return instance;}}

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A single-instance design pattern for Java design patterns