You can use the HashMap but the probability of working fine depends on the way we use it. For instance, consider the HashMap of configuration properties, if the HashMap initialization was done by using just one thread, and the remaining threads do the task of reading from the map, then HashMap would work perfectly well.

The problem arises when there is at least one thread that updates the Map by means of adding, updating, or deleting the map content. The put() method of the map resizes the map that can cause a deadlock or infinite loop while the threads operate. Hence, during such scenarios, we can use the HashTable or ConcurrentHashMap.