“Effective Java” is a well-known book written by Joshua Bloch, which provides best practices and guidelines for Java programming. It covers various aspects of Java development and offers valuable insights to help developers write efficient and robust code.

1. Use of Static Factory Methods: The book recommends using static factory methods instead of public constructors to create objects, as they provide more flexibility and descriptive names.

2. Prefer Interfaces over Abstract Classes: By favoring interfaces, you can achieve greater flexibility in your code, as classes can implement multiple interfaces, but only extend one abstract class.

3. Beware of the Pitfalls of String Concatenation: The book advises against using the ‘+’ operator for string concatenation within loops, as it can lead to inefficient memory usage.

4. Avoid Unnecessary Object Creation: Creating objects can be expensive, so it’s best to reuse existing ones whenever possible, for example, by using immutable objects.

5. Use Enums Instead of Constants: Enums offer a more structured approach to represent a fixed set of constants, providing type safety and maintainability.

6. Understand and Use Generics: Generics allow you to write type-safe and reusable code. Using them effectively is vital for modern Java programming.

7. Follow Best Practices for Exception Handling: Proper exception handling is essential for writing robust and maintainable code.

8. Take Advantage of Java’s Concurrency Utilities: Java provides powerful concurrency utilities, like Executors and ConcurrentHashMap, which should be used instead of manual thread management.

9. Use the Override Annotation: By using the @Override annotation, you can avoid accidental mistakes when overriding methods.

10. Mindful Use of Serialization: Serialization can introduce security risks, so it’s important to approach it cautiously and consider implementing the Serializable interface carefully.

Remember that these points only scratch the surface of the valuable information “Effective Java” offers, and I highly recommend reading the book for a comprehensive understanding of Java best practices.