Introduction to Java Programming

Java is a programming language and platform used to create applications that run on various devices like computers, mobile phones, and servers.

It was developed in 1995 by a team at Sun Microsystems, led by James Gosling.

The key idea of Java is "Write Once, Run Anywhere," meaning you write the program once, and it works on any device with Java installed.

This makes Java ideal for building software that works across different platforms.

Today, Java is widely used for websites, mobile apps, games, and large business systems. It is maintained by Oracle Corporation, which regularly updates it to keep it modern and efficient.

Java is a nearly object-oriented, high-level programming language, it is an open-source and platform-independent programming language. The latest version of Java is JDK 23, which was released on September 17, 2024. JDK 21 is the latest Long-Term Support (LTS) release.

Types of Java

Java can be categorized into different types based on its usage and application. Here are the main types of Java.

• Java SE (Standard Edition) - For building standalone and core applications.

• Java EE (Enterprise Edition) - For creating large-scale, distributed, and web-based enterprise applications.

• Java ME (Micro Edition) - For developing applications for resource-constrained devices like mobile phones and IoT devices.

Why Learn Java in 2025? Key Features and Advantages

• Runs Everywhere: Java programs work on any device with a Java Virtual Machine (JVM), making them very flexible.

• Great Community Support: Millions of developers share tutorials, forums, and resources to help you learn Java.

• Easy to Learn: Java has simple and clear syntax, making it beginner-friendly.

• Used Everywhere: Java powers websites, Android apps, business tools, games, and even data science projects.

• Fast and Reliable: Java is fast, secure, and handles memory automatically, making it robust and trustworthy.

• High Demand for Jobs: Many companies still need Java developers, offering good career opportunities.

• Keeps Getting Better: Java gets regular updates with new features to stay modern and useful.

Applications of Java in Real-world Projects

• Web Apps: Frameworks like Spring and Hibernate help build strong and scalable web applications.

• Android Apps: Java is the main language for creating Android apps.

• Enterprise Systems: Banks, healthcare, and online stores use Java for their backend systems.

• Big Data: Tools like Apache Hadoop and Kafka use Java to handle large amounts of data.

Java Program

Set of instructions written according to Java syntax (Rules). Click here to learn how to set up a Java development environment.

There are 3 stages of Java program development

• Coding and Composition: Developing a program according to Java syntax is called coding.

• Compilation: Converting the Java program into bytecode using javac a compiler is called a compilation

• Execution: Converting the bytecodes of .class file into machine-level language using JVM (Java virtual machine)

Note

• JVM is an interpreter.

• All bytecodes will be stored in a .class file.

• All the Java programs should be saved with public filename.java. (only one file is created in a program as public).

Writing Your First Program in Java

Let’s create a simple Java program to test your setup.

Using IntelliJ IDEA:

1. Open IntelliJ IDEA and create a new Java Project.

   • Select File > New > Project.

   • Choose Java and set the JDK.

2. Create a new Java Class file (e.g., MasterBackend).

   • Right-click on the src folder, select New > Java Class, and name it MasterBackend.

3. Write the following code:

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

4. Run the program:

   • Click the green Run button in the toolbar or right-click the file and select Run MasterBackend.main().

   • You should see Hello, Master Backend! printed on the console.

Execution with command line

The general syntax for compilation

javac filename.java

The general syntax for run

java classfileName

Conclusion

To sum up, Java is one of the most flexible and widely used programming languages globally. It’s easy to learn, works on any platform, and has a large, supportive community, making it a great option for developers at any level.

Java is used in various areas like web development, Android apps, business systems, and big data, offering many career opportunities. As Java keeps improving and adapting to new needs, it continues to hold a solid and promising spot in the world of software development.