Java 21: the dawn of simplicity
With Java 21, this development of the language continues with many exciting features and enhancements targeted at making the development easier, more productive, and competitive in view of modern challenges. Probably the most impressive point related to Java 21 is the possibility to reduce boilerplate code and streamline development by minimizing, in some instances, the need for public void methods, particularly inside main methods and test environments.
In this article, we take a closer look at what this change means for Java developers and how it forms part of more general simplicity and modernizing trends for Java.
1. The Legacy of public static void main(String[] args)
Traditionally – and until now, the only – signature to start any Java application used the following standard entry point method signature:
public static void main(String[] args) {
// Your code here
}
This method serves as the main entry point for Java programs, and it’s been a required boilerplate since the inception of the language. The public static void part has remained unchanged for a long time, despite being somewhat verbose and unnecessary for simpler applications or smaller scripts.
Public: This keyword makes the method accessible from outside of the class, which makes it guaranteed that the JVM will find and invoke this method as the program starts its execution. Static: This keyword suggests that this method belongs rather to the class itself than to an object of that class. That is necessary because the JVM invokes the method without creating an object of the class. Void: This keyword declares that this method returns nothing.
The name of the entry point method.
String[] args: These define the command-line arguments passed to the program.
While this has served well and been reliable for launching Java applications, the verbosity of the signature has always been a constant nuisance to many developers-especially to those developers who have become used to other languages like Python or JavaScript, whose entry points have no such level of wordiness. It is with that in mind that I move on to the next section. 2. Modern-Day Simplification
Java in recent times has been trending into making the language friendlier and more modern, especially for new developers. In recent releases like Java 17 (LTS) and now Java 21, a lot of focus has been given to syntactic simplifications, removal of obsolete features, and use of newer paradigms.
Some of the important simplifications of recent versions of Java are as follows:
Text Blocks: Allows easier handling of multiline strings.
Records: Will write less boilerplate code for classes that hold just data.
Pattern Matching: It simplifies the complex conditional logic to check the type of variables.
Switch Expressions: It was introducing concise syntax to the switch statements.
Java 21 continues this trend, and removing the need for public void methods in these situations is a part of this wider drive for simplicity.
3. No More Boilerplate for Entry Points: The Case of main Method
It is an attempt at reducing boilerplate code for public static void main(String[] args) in Java 21, where it is not required in the applications. Yes, the usual main method would still be there and work just the same; however, new features are coming up in Java 21 that allow developers to write short code snippets and enhance readability.
Key Changes:
Smaller Program Entry Points: Programmers could write programs that don’t necessarily need the full public static void main(String[] args) signature. Small utility programs, for example, could get by with it, scripts, or even microservices whereby the wordy method signature is a requirement of Java; thus, the language would become somewhat more adequate for lightweight applications and rapid prototyping.
Theoretically, with Java 21, removal of void return types in tests could be allowed in certain environments, say testing. It would clean up the code a bit since many methods in this application are of type void. That reduces the necessary boilerplate code that needs to be written for tests, as no return types or even access modifiers are needed.
Example Before Java 21:
public class MainApp {
public static void main(String[] args) {
System.out.println("Hello, Java!");
}
}
System.out.println("Hello, Java!");
This decreased syntax can, in fact, be closely compared to that of scripting languages because it allows developers to create simple scripts and lightweight applications where an excess structure is just not needed. It’s with this design to actuate Java to be further competitive with those other languages for simplicity in use. 4. Streamlining Unit Testing
Removing redundant public void methods is another welcome improvement in unit testing. Compared to earlier versions of Java, developers declare test methods using the syntax below with frameworks like JUnit:
public void testSomething() {
// Test code
}
Until now, such a method had to be declared with a void return type, even if this was semantically otiose. In Java 21, a developer won’t need to declare the void methods like these, and tests could be cleaner and more straightforward.
This simplifies the code by reducing unnecessary boilerplate and makes it more about the logic than syntax noise. In particular, in TDD environments, this pays off when you want to implement many short, focused test methods quickly.
5. Why It Matters: Impact on Developer Experience
This move to remove the necessity of having public void methods for certain cases aligns with the general effort to modernize Java, making it less verbose and thus easier to use by new programmers and more efficient for experienced programmers.
Easier Learning Curve: One of the common complaints for newcomers to Java is how much boilerplate code is required simply to get up and running. By simplifying this entry point and reducing the need for public void methods, Java will be less daunting for new developers, who will then use the language more.
Improved Readability: Boilerplate code will be reduced, which would enhance readability for small programs, scripts, and tests. The developers need to remember verbose method signatures less and write logic instead.
Speed of Development: While removing redundancy in code and reducing method declarations can result in faster development times, especially when performing small tasks, utilities, and even when writing prototype applications.
6. Backward Compatibility and the Future of Java
Java’s always been one of those languages that was very backward compatible. With the simplifications coming in with Java 21, the traditional public static void main(String[] args) method would still work just fine. This means applications are not going to break, nor are developers who stick with the older style going to have to stop using it.
But for those who would leap at the opportunity to move on toward newer, brighter things, Java 21 opens the modern, slimmed-down way of coding that makes it lighter-feathered and more agile in most contexts where minimalism is the keyword.
As Java continues its quest to innovate, we are likely to see in the future much more features focused on simplicity, developer experience, and adaptability to today’s modern ways of coding.
Conclusion: A Step Toward a Simpler Java
Java 21, therefore, will mark a great turn in the way this language will buckle up to meet modern programming demands by significantly reducing the need to declare public void methods. Java is becoming flexible and approachable without losing performance, security, and robustness, features that have positioned it as a cornerstone in enterprise development, by removing unnecessary verbosity in entry points and unit tests.
As Java 21 keeps attracting more and more attention, such changes are definitely going to be well received by developers who seek to produce cleaner and faster code, making Java one of the most versatile and future-proof programming languages.
