Need to add multiple values to a key in a Java HashMap but can't figure out how to do it? Here are three examples of how to solve the multiple values per key problem in Java.

I have an arraylist of approximately 9000 strings. Most of these are duplicates. I need to figure out a way to count each distinct item, without prior knowledge of what is in the arraylist, and ...

Developers can choose between fail-fast and fail-safe iterators in Java. Here we compare and contrast the two so you'll know which will fit your situation.

Get started modeling entities and relationships for Java data persistence, using an example application based on Java 21 with Hibernate 6.3.