Best Practices for Using Java

#java #bestpractices #developers #javadevelopers

Java Best Practices for Developers:
Keeping Up with the Times -
Enterprise development still heavily relies on Java, and since the language and its ecosystem are always changing, so too must best practices. The following are some essential guidelines for Java developers in 2024:

Accept Unchangeability - Make items that are unchangeable once they are created by using immutable objects. This improves debugging, increases thread safety, and makes it easier to understand how code behaves. For class fields, use the final keyword; for object construction, think about using builders or copy constructors.

public class User {
private final String name;
private final int age;

public User(String name, int age) {
this.name = name;
this.age = age;
}

// Getters but no setters
public String getName() { return name; }
public int getAge() { return age; }
}

Leverage Generics for Type Safety - Generic Classes and Methods: Utilize generics to develop code that works with various data types without compromising type safety. This reduces casting errors and improves code maintainability.

public class Pair {
private T first;
private T second;

public Pair(T first, T second) {
this.first = first;
this.second = second;
}

public T getFirst() { return first; }
public T getSecond() { return second; }
}

Optimize for Performance -

Avoid Premature Optimization: Focus on writing clear and maintainable code first. Measure performance bottlenecks later and optimize only when necessary.
Utilize Profiling Tools: Tools like JProfiler or YourKit can identify performance bottlenecks in your code, allowing you to target optimizations effectively.
Consider Functional Programming Techniques: In Java 8 and above, streams and lambdas can offer concise and efficient ways to process data, potentially leading to performance improvements.

Embrace Concurrency Effectively -

Concurrency Utilities: Java provides a rich set of concurrency utilities like threads, thread pools, and concurrent collections. Utilize these tools effectively for parallel processing and improved responsiveness but be cautious of potential concurrency issues like race conditions.
Immutable Objects for Thread Safety: As mentioned earlier, immutable objects can simplify thread safety concerns, as their state cannot be modified after creation.

Stay Updated with the Latest Java Features -

Java 17 (LTS) and Beyond: Java releases new features every six months. Familiarize yourself with the latest LTS version (Java 17 as of May 2024) and consider incorporating its features (like sealed classes or switch expressions) into your projects when appropriate.
Modern Libraries and Frameworks: The Java ecosystem boasts a vast array of mature libraries and frameworks. Choose tools that align with your project requirements and stay updated on their latest versions to benefit from bug fixes, security patches, and new functionalities.

Automate Testing and Builds -

Unit Tests: Write comprehensive unit tests to ensure code functionality and catch regressions early in the development cycle. Frameworks like JUnit are popular choices.
Integration Tests: Complement unit tests with integration tests to verify how different parts of your application interact.
Continuous Integration/Continuous Delivery (CI/CD): Implement CI/CD pipelines to automate builds, testing, and deployments. This streamlines development workflows and reduces manual errors.

Top comments (2)

Karl Heinz Marbaise • May 19

If we are talking about more or less recent versions of Java (JDK17+) we should use records instead of plain old classes to keep that clean and easy...so as your example the User class is done easier like this:

public record User(String Name, int age) {}

while I have to say using an age like this is the wrong approach... better use a date of birth but that's a different discussion like this:

  record Person(String name, LocalDate dateOfBirth) {
    int age() {
      return Long.valueOf(ChronoUnit.YEARS.between(dateOfBirth(), LocalDate.now())).intValue();
    }

    @Override
    public String toString() {
      return "Person{" +
             "name=" + name +
             ", dateOfBirth=" + dateOfBirth +
             ", age=" + age() +
             '}';
    }
  }

And your User class misses equals and hashCode...

Using builders contradicts the idea of immutable classes (also valid for records).
Immutability is not easy to reach... but a very good approach
The example for type safty is simply wrong because the generic is not used correctly...
``java
public class Pair {
private final T first;
private final T second;

public Pair(T first, T second) {
this.first = first;
this.second = second;
}

public T getFirst() {
return first;
}

public T getSecond() {
return second;
}
}
`
In exactly such case I strongly recommend to use nominal type which means a record and name it accordingly.. instead of using a default Name pair... Things like record Point(int x, int y) instead of Pair<Integer> this lacks the information about the name...Also nominal types like records etc. can easier being used in relationship with sealed class to build algebraic types or union types etc... also related to the used in pattern matching...

The current LTS version from Oracle side is JDK 21 oracle.com/java/technologies/java-... So I would recommend always use the most recent version ... also move to the most recent versions...
The last JDK version is JDK 21 openjdk.org/projects/jdk/21/ (done in september 2023) while JDK 17 in september 2021...