Class Fundamentals class classname { type instance-variable1; type instance-variable2; // … type instance-variableN; type methodname1(parameter-list) { // body of method } type methodname2(parameter-list) { // body of method } // … type methodnameN(parameter-list) { // body of method } } Here is a class called Box that defines three instance variables: width, height, and depth.…
Decision Constructs Java supports two selection statements: if and switch. These statements allow you to control the flow of your program’s execution based upon conditions known only during run time. The if-else Statement The if statement is Java’s conditional branch statement. It…
Why Data Types are Important in Java? Java’s Primitive Types Java defines eight primitive data types: byte, short, int, long, float, double, char and boolean. Group Description Integers This group includes byte, short, int, and long, which are for whole-valued…
The History and Philosophy of Java Object-Oriented Programming Java Development Kit (JDK) The Java Development Kit is an implementation of either one of the Java Platforms; Standard Edition, Enterprise Edition, of Micro Edition platforms released by Oracle Corporation in the…
What is JPA Entity Relationship? Multiplicities are of the following types. Create JPA Entity with One-to-One Relationship Reference: In this example, we create Instructor and InstructorDetail entities and we make a one-to-one mapping between them. Create a new project…
Collections Overview The Java Collections Framework standardizes the way in which groups of objects are handled by your programs. Collections were not part of the original Java release but were added by J2SE 1.2. Prior to the Collections Framework, Java…
What is Java System Properties and Spring Application Configuration? Java System Properties Java maintains a set of system properties for its operations. Each java system property is a key-value (String-String) pair. For example, one such system property is “java.version”=”1.7.0_09“. All…
What is JSON, HTTP Methods, REST API and Web Server? JSON JSON Syntax Rules HTTP Methods The Hypertext Transfer Protocol (HTTP) is designed to enable communications between clients and servers. HTTP works as a request-response protocol between a client and…
Class Fundamentals A Java class is often used to represent a concept. A Java class is often used to store or represent data for the construct that the class represents. For example, you could create a model (a programmatic representation)…