1. Quick Introduction

Java is one of the most popular programming languages on the market today. According to the TIOBE index of 2024, it is the 4th most widely used language. Why have so many companies adopted Java over the years? In this article, we’ll delve into the Java Essentials, exploring the language’s strengths.

2. A High-level Programming Language

Java is a high-level programming language. This means that when you write a program in Java, you don’t have to worry about low-level details like memory management, register management, etc. The developer who programs in Java doesn’t need to have any knowledge of the hardware (CPU, RAM) on which his program will be run. All this makes a Java program simpler to write and easier to understand. This is not the case with low-level languages such as C or Assembly.

3. Write Once, Run Anywhere

Java is a programming language that is both compiled and interpreted. Java is compiled because its source code is transformed into byte-code during the compilation phase. The virtual machine (JVM) then interprets the byte-code during the execution phase..
Java owes its portability to the use of the JVM. Indeed, any environment (Windows, Linux, macOS, cell phone, Web browser) with a Java virtual machine is capable of executing a compiled Java program.
This portability is the origin of the slogan: Write Once, Run Anywhere.

4. Object-Oriented Language

Java owes much of its renown to the fact that it is an object-oriented language. Object-oriented programming (OOP) is a programming paradigm inspired by real life. This paradigm conceives a computer program as a set of interacting objects. An object is thus characterized by its properties and behaviors. Properties correspond to attributes (size, age, gender, etc.) and behaviors correspond to functions that can be called up on the object. The advantages of OOP over other programming paradigms include code modularity, ease of maintenance, and reusability.

5. Robustness and Security

In computer science, robustness is the ability of a computer system to cope with errors during execution and with erroneous input.
The following mechanisms guarantee the robustness of the Java language:

5.1. Memory management

Memory management is undoubtedly the most important pillar of the Java language’s robustness. Thanks to automatic memory management via the Garbage Collector, Java programs are less prone to memory leaks.

5.2. Exception handling

Java has an advanced exception-handling mechanism. An exception is an event that occurs during program execution and prevents the program from continuing normally.
In Java, when an exception is raised, the developer has the option of either handling it (try-catch) or propagating it (throws) to a higher level. This helps in writing more reliable and fault-tolerant code.

5.3. Strong Type Checking

Java is a statically-typed language, meaning that variable types are explicitly declared during compilation. This helps catch type-related errors at compile time, enhancing code robustness.

5.4. Security

Java is well known for its robust security mechanisms, which were an integral part of its design.
Among the most important points of this security are :

• Sandboxing and Security Manager: Java applications run within a sandboxed environment, which restricts their access to certain system resources. The Security Manager, a component of the Java Runtime Environment (JRE), defines and enforces the access rules. This helps prevent untrusted code from performing malicious actions.
• Bytecode Verification: Before the JVM executes the byte-code, it goes through a verification process to check that it conforms to the specifications.
• Classloaders: Java’s classloaders provide a mechanism for dynamically loading classes at runtime. They contribute to security by allowing the isolation of classes and preventing unauthorized access to sensitive classes or resources.

6. Multithreading

Multi-threading is the ability of a program to ensure several execution streams in parallel.
Java has a set of libraries that facilitate the implementation of multithreaded programs.

7. High Performance

As mentioned above, Java applications run on a virtual machine (JVM), a layer of abstraction between byte-code and hardware architecture. One might think that this would significantly impact performance.
However, thanks to concepts such as Just In Time Compilation (JIT) and optimized memory management, including garbage collection, Java applications approach the performance of native applications.

8. Strong Community and Resources

There’s a reason why Java is ranked as the 4th most popular programming language in 2024 according to the TIOBE index. Java has a very strong developer community. When you encounter a problem in Java, there’s a very good chance that another developer has already had it before you.
A simple search in a forum like StackOverflow and you’ll have the answer to your concern. Java’s popularity also means that there are many frameworks and libraries available to address common development issues.
The most popular Java frameworks include Spring, GWT, JSF, Hibernate, etc.

9. Conclusion

To conclude this blog on Java Essentials, we’ve seen that Java is a high-level, object-oriented programming language, enabling you to write programs without worrying too much about so-called low-level aspects such as memory management. We have also seen that a program written in Java on one operating system can be run on any other system, thanks to the existence of the virtual machine. Finally, we’ve seen that the very strong community that exists around Java means that most of the problems you’ll encounter, someone before you will already have had.

10. References

1) OCP Oracle Certified Professional Java SE 17 by Khalil A. Mughal and Vasily A. Strelnikov
2) Oracle Java Documentation