What is EJB in Java and How to Implement it? What is Dictionary in Java and How to Create it? Moving on with this SOLID Principles in Java article. When we are talking about single principle responsibility, we would say, there are too many reasons for the class to change; hence, it doesn’t fit properly in the single responsibility principle. Robert C. Martin gave five object-oriented design principles, and the acronym “S.O.L.I.D” is used for it. So practice this principle whenever possible to make your coding better. Struts 2 Tutorial – One Stop Solution for Beginners. We should be able to extend those classes without worrying if those base classes can support our extensions. Singleton Class in Java – How to Use Singleton Class? So, basically, whenever you write code, you have to keep these core principles in your mind, and actually, to be honest, you have to take these principles as your base map while writing those codes to make it efficient and effective. There is a base interface Shape. What is Trim method in Java and How to Implement it? What is BlockingQueue in Java and how to implement it? For example, a single logging interface for writing and reading logs is useful for a database but not for a console. How To Implement Volatile Keyword in Java? Let us say that there is a Restaurant interface which contains methods for accepting orders from online customers, dial-in or telephone customers and walk-in customers. A Beginner's Guide to Java and Its Evolution. They also form the. They are independent now.There will be no need to do any dummy implementation or throw an UnsupportedOperationException as each interface has only methods it will always use. What is Machine Learning in Java and how to implement it? BufferedReader in Java : How To Read Text From Input Stream. It helps us conform to the “is-a” relationship.We can also say that subclasses must fulfill a contract defined by the base class. The correct solution for above problem will be: Java HashMap – Know How to Implement HashMap in Java, What is LinkedHashSet in Java? How to Write Hello World Program in Java? Here the class has multiple reasons to change, and few of them are the modification of file output, new database adoption. Since the above code(OnlineClientImpl.java) is for online orders, throw UnsupportedOperationException. One should note that as per the definition of Rectangle, following must always hold true given the data below: In case, we try to establish ISA relationship between Square and Rectangle such that we call “Square is a Rectangle”, above code would start behaving unexpectedly if an instance of Square is passed Assertion error will be thrown in case of check for area and check for breadth, although the program will terminate as the assertion error is thrown due to failure of Area check. As the types of shapes grows this becomes messier as AreaCalculator keeps on changing and any consumers of this class will have to keep on updating their libraries which contain AreaCalculator. Even if you have given a Visa card, he will not put out a Visa machine for swiping your card. What is System Class in Java and how to implement it? Do you remember installing extensions in your chrome browser? We start with creating a class for our first shape Rectangle which has 2 attributes length & width. For example, it’s tempting to say that a circle is a type of ellipse but circles don’t have two foci or major/minor axes. Robert C. Martin gave five objected oriented design principles, and the acronym S.O.L.I.D is used for it. What is Conditional Operator in Java and how to write it? In another example, a Book class has properties to store its own name and text. How to Find the largest number in an Array in Java? Top 30 Patterns in Java: How to Print Star, Number and Character, Know all about the Prime Number program in Java.