Singleton class made easy in Scala
Singleton Singleton is a notorious OOPs design pattern, which allows only one instance of the class to be created at any point of time. This is used primarily for heavy weight classes that are not supposed to be created for every instantiation request. Private constructor (Ingredient #1) To make the class singleton the key ingredient is Private Constructor in the class. Since private constructor is not accessible from outside of the class, we can restrict the creation of the objects. Similar to Java, Scala allows us to make the primary constructor as private so that we can use method definition to perform controlled creation of objects. Companion Object (Ingredient #2) Companion object is analogous to utility class in Java. A utility class in Java will contain only static methods, thus makes easy to invoke methods without object. In Scala, a companion object will have the same name of the class in the same file and all the methods that are declared will be static....
Comments
Post a Comment