Java Design Patterns -- Singleton Design Pattern

Singleton Design PatternThe singleton design pattern is one of the Gangs of Fourdesign patterns, one of the simplest design patterns in Java, and belongs to the Creational Design Patterncreational design pattern. It looks like a very simple design pattern, but when it comes to implementation, it brings up a lot of problems. Singleton Design PatternThe implementation of the singleton design pattern in Java has always been a controversial topic.

Singleton Singleton

• The singleton pattern restricts the instantiation of a class, ensuring that only one instance of a class exists in the Java Virtual Machine.
• Singleton classes must provide a global access point to obtain instances of the class.
• The singleton pattern is used for logging, driver objects, caches, and thread pools.
• The singleton design pattern is also used in other design patterns like Abstract Factory, Builder, , Prototype, Facadeetc.
• The singleton design pattern is also used for Core Java classes such as java.lang.Runtime,java.awt.Desktop