Behavioral Observer java AccountService Logger LoginStatus Mailer Observer ObserverPatternExample Protector Subject User src Main Observer Subject Creational Abstract Factory crs AbstractFactory AbstractFactoryPatternExample Bank BankFactory BussinessLoan EducationLoan FactoryCreator HDFC HomeLoan ICICI Loan LoanFactory SBI java author Author HistoryAuthor TechnologyAuthor book Book HistoryBook TechnologyBook factory AbstractFactory impl AuthorFactory BookFactory FactoryImpl Main Builder src CreateStudent Student StudentBuilder StudentConcreteBuilder Factory Method java Client Ship Transport TransportFactory TransportType Truck src ApplePhone NokiaPhone Phone PhoneFactory PhoneType RunDeMo SamsungPhone Prototype java MainClone User src Animal Bird Fish PrototypePattern Singleton DoubleCheckLockingSingleton DoubleCheckMain SingletonDoubleCheck Eager Eager EagerSingleton Lazy Lazy1 Lazy2 Lazy3 LazySingleton