How to avoid deadlock in Java? Is one of the popular Java interview question and flavor of the season for multi-threading, asked mostly at a senior level with lots of follow up questions. Even though the problem looks very basic but most of the Java developers get stuck once you start going deep. Interview questions start with, "What is a deadlock?" The answer is simple when two or more threads are waiting for each other to release the resource they need (lock) and get stuck for infinite time, the situation is called deadlock. It will only happen in the case of multitasking or multi-threading.