Overview of the Fork/Join Framework in Java The Fork/Join framework in Java is an example of the divide and conquer strategy. It is best used for scenarios where you have multiple tasks that can be executed individually. There are two important classes: RecursiveTask<T> and RecursiveAction. While RecursiveTask returns a value, RecursiveAction doesn’t (Similar to Callable … Read more
Overview Hashtable and HashMap are common data structures to store key-value data in your Java application. While having similarities, there are some crucial differences you need to know as a Java developer. Let’s discuss the differences between these two data structures in this post. Hashtable is thread-safe, HashMap is not Consider the following code using … Read more
Overview While preparing for the OCP 17 exam, I created some notes to aid my learning. This is the first of many posts in this series. I hope you find it helpful. Java Exception Handling Cheat Sheet The Throwable family Checked vs. unchecked exceptions Overriding methods with declared exceptions Example RuntimeException Checked exceptions Error Exception … Read more
Overview @ManyToOne and @OneToMany are standard mappings in Hibernate. Understanding how to use them correctly is the key to mapping entities efficiently in Hibernate. In this post, I will show you how to use these annotations and give examples to demonstrate use cases. The analogy I use is schools and students. In real life, schools … Read more
Overview Imagine this scenario, you have a legacy database that store weather data. The previous developer, due to various reason, store the temperature in the following format: id location temperature capture_date 1 Hanoi 30.50 C 2023-07-31 22:10:30.000 2 New York 95.20 F 2023-07-31 22:10:30.000 As you can see, the temperature stored in a sub-optimal way … Read more
Overview One of the lesser-known yet powerful annotations in Hibernate is @ColumnTransformer. This annotation let us apply SQL transformations on entity properties when interacting with the database. You can think of this annotation as a two way converter. A real life use case Let’s consider a weather app that initially use Kelvin scale to store … Read more