BayaReddy Learning Notes

About the Java Technology Java technology is both a programming language and a platform. The Java Programming Language The Java programming language is a high-level language that can be characterized by all of the following buzzwords: Simple Object oriented Distributed Multithreaded Dynamic Architecture neutral Portable High performance Robust Secure The Java Platform The Java platform has two components: The  Java Virtual Machine The  Java Application Programming Interface  (API) How Will Java Technology Change My Life? Get started quickly : Write less code :  Write better code :  Develop programs more quickly :  Avoid platform dependencies :  Write once, run anywhere : Distribute software more easily : Object Any entity that has state and behavior is known as an object. Class It is a logical entity. Polymorphism When  one task is performed by different ways Abstraction Hiding internal details and sho

Bean id vs name: >Only 1 id, but Many names Special characters like #, @, $, *, /, and more are not allowed in the id attribute.  If you add one of these special characters to the id, you get an XmlBeanDefinitionStoreException thrown when the configuration is read by the container Ex: < bean id ="foo" name = "myFoo,kingBean,notBar" class ="com.intertech.Foo"/> >Names Still Must Uniquely Identify when the id of a bean matches the name of another bean, an BeanDefinitionParsingException Ref: https://www.intertech.com/Blog/clarifying-spring-framework-ids-and-names/ Autowiring: ~@Qualifier : https://www.mkyong.com/spring/spring-autowiring-qualifier-example/