Java (Base language)

To learn more about advanced Java topics such as the Java virtual machine, collections language, and many more topics, visit baeldung.com ⧉.

Refactoring.guru ⧉ has information about general code smells.

• Be aware of common Java gotchas ⧉.
• Avoid acronyms and abbreviations that may not be clear to others.
• Name methods and variables after what they mean. Before giving a name, consider the responsibility of that piece of code (Naming 101: A Programmer's Guide on How to Name Things ⧉).
• Return empty collections instead of returning null elements (reference ⧉). It saves the efforts needed for testing on null elements.
• Efficiency: Use StringBuilder or StringBuffer ⧉ for String concatenation
• Refactor your code regularly, especially when your classes or methods become too big (Rule of 30 – When is a Method, Class, or Subsystem Too Big? and Avoid basic style errors ⧉)
• Remember to test the parameters of public methods for illegal values. These methods shouldn't crash because of a NullPointer.
• Order class members by scope from private to public (Ordering Class Members by Scopes and Separate public and private members ⧉)
• Minimize the accessibility of class members. It enforces information hiding or encapsulation ⧉.
• Avoid hardcoded values.
• Use lazy initialization if performance is critical, or use caching ⧉ if necessary.

Utility and Helper Classes

• Utility class: They include only static methods and are stateless. Don't create an instance of such a class.
• Helper class: They can be utility classes, or they can be stateful or require an instance. It can be any class whose design is to aid another class.
• Try to make the name of the utility or helper class more specific (e.g., AdministrationHelper, LoginHelper instead of Helper).

More Tips

• If you use functional interfaces, use the standard Java ones. If you want to understand the functional style, consult the page: Understand the functional style ⧉.
• If you want to use newer Java features, look at Modernize old code ⧉.
• Have a look at common sources of complexity ⧉.

Stack Exchange: Software Engineering

• When do you use float, and when do you use double ⧉
• What's wrong with circular references? ⧉
• Are null references really a bad thing? ⧉
• Exceptions: Why throw early? Why catch late? ⧉
• How do quick & dirty programmers know they got it right? ⧉
• Why is Global State so Evil? ⧉
• How would you know if you've written readable and easily maintainable code? ⧉
• How do you know you're writing good code? ⧉

---

Last update: July 16, 2023

Comments