What is it? How do define it? How to use it? Why use it?What is Generics?• Generics provides abstraction over Types > Classes, Interfaces and Methods can be Parameterized by Types (in the same way a Java type is parameterized by an instance of it)• Generics makes type safe code possible … Read More Generics
Seven Major New Features• Generics• Autoboxing/Unboxing• Enhanced for loop (“foreach”)• Type-safe enumerations• Varargs• Static import• MetadataAutoboxing/Unboxing of Primitive Types• Problem: (pre-J2SE 5.0) > Conversion between primitive types and wrapper types (and vice-versa) > You need manually convert a primitive type to a wrapper type before adding it to a collectionint i =… Read More J2SE 5.0 Language Features
What is a Collection? • A “collection” object — sometimes called a container — is simply an object that groups multiple elements into a single unit• Collections are used to store, retrieve, manipulate, and communicate aggregate data > Typically, they represent data items that form a natural group, such as a poker hand (a… Read More Collection Framework
What is Garbage Collection (GC)?• The Java virtual machine’s heap stores all objects created by a running Java application.• Objects are created by the program through new keyword, but never freed explicitly by the program > No need to call free().• Garbage collection is the process of automatically freeing objects that… Read More Gargbage Collection (GC)
Abstract Class & Java InterfaceWhat is an Abstract Class?Abstract Methods● Methods that do not have implementation (body)● To create an abstract method, just write the method declaration without the body and use the abstract keyword – No { }● For example, // Note that there is no body public abstract void someMethod();Abstract… Read More Abstract Class & Java Interface
What is an Exception?? Exceptional event – typically an error that occurs during runtime? Cause normal program flow to be disrupted? Examples – Divide by zero errors – Accessing the elements of an array beyond its range – Invalid input … Read More Java Exception Handling
What is Polymorphism?● Polymorphism– The ability of a reference variable to change behavior according to what object instance it is holding.– This allows multiple objects of different subclasses to be treated as objects of a single super class, while automatically selecting the proper methods to apply to a particular object based on the subclass it belongs to.Example: Polymorphism●… Read More Core Java – Polymorphism
Suresh Sekar's Architecture Introspection 