JAVA – Overview

What is JAVA?

Java is a versatile programming language and platform known for its high level of security, robustness, and object-oriented nature. It was originally developed by Sun Microsystems (now a subsidiary of Oracle) in 1995, with James Gosling credited as its creator. Initially named Oak, the language was later renamed to Java due to trademark conflicts.

Java is considered a platform because it provides a runtime environment (known as the Java Runtime Environment or JRE) and an extensive Application Programming Interface (API) that enables the execution of Java programs across different hardware and software environments.

Java finds extensive usage in various domains, and it is estimated that around 3 billion devices run Java. Some common applications of Java include desktop applications (such as media players and antivirus software), web applications (like online booking platforms and educational websites), enterprise applications (including banking systems), mobile applications (particularly on the Android platform), embedded systems, smart cards, robotics, and games.

There are four main types of applications that can be developed using Java:

1) Standalone Applications: These are traditional software applications, also known as desktop or window-based applications. Standalone applications need to be installed on individual machines and can include programs like media players and antivirus software. Java provides AWT (Abstract Window Toolkit) and Swing libraries for creating standalone applications.

2) Web Applications: These applications run on the server side and generate dynamic web pages. Technologies like Servlets, JavaServer Pages (JSP), Struts, Spring, Hibernate, and JavaServer Faces (JSF) are commonly used for developing web applications in Java.

3) Enterprise Applications: Enterprise applications are distributed systems designed to handle complex business processes. They often require features like high-level security, load balancing, and clustering. Java’s Enterprise JavaBeans (EJB) technology is commonly used for developing such applications.

4) Mobile Applications: Mobile applications are specifically developed for mobile devices. In the context of Java, Android and Java Micro Edition (Java ME) are used for creating mobile applications.

Java offers different editions or platforms to cater to specific development needs:

1) Java SE (Java Standard Edition): This is the core platform for general Java development. It provides essential APIs for programming, including topics such as object-oriented programming, strings, regular expressions, exceptions, multithreading, networking, graphical user interfaces (AWT and Swing), reflection, and collections.

2) Java EE (Java Enterprise Edition): Java EE is an extension of Java SE and is primarily used for developing web and enterprise applications. It builds upon the Java SE platform and includes technologies like Servlets, JSP, web services, Enterprise JavaBeans (EJB), Java Persistence API (JPA), and more.

3) Java ME (Java Micro Edition): Java ME is a platform specifically designed for developing applications on resource-constrained devices, such as mobile phones and embedded systems.

4) JavaFX: JavaFX is a platform used for creating rich internet applications (RIAs) with a lightweight user interface API. It enables the development of visually appealing and interactive applications that can run on various platforms.

Java Program Example

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Practice Question

Question: What are the key features of the Java programming language?

Answer: The Java programming language is known for its distinctive features, which include:

1. Object-Oriented Programming (OOP): Java supports OOP principles such as encapsulation, inheritance, and polymorphism, allowing for modular and reusable code.
2. Platform Independence: Java programs are compiled into bytecode, which can run on any platform with a Java Virtual Machine (JVM). This “write once, run anywhere” capability makes Java highly portable.
3. Garbage Collection: Java provides automatic memory management through its built-in garbage collector, which frees developers from explicitly managing memory allocation and deallocation.
4. Exception Handling: Java has a robust exception handling mechanism that enables the detection and handling of errors or exceptional conditions during program execution, promoting reliable and resilient code.
5. Multi-threading: Java supports concurrent programming through its built-in threading capabilities, allowing for the execution of multiple threads simultaneously and efficient utilization of system resources.
6. Security: Java incorporates security features like bytecode verification, sandboxing, and a security manager to ensure secure execution of programs and protect against malicious actions.
7. Rich API: Java provides a vast collection of standard class libraries and APIs that cover a wide range of functionality, simplifying development tasks and accelerating the creation of applications.