Listeners are very useful in the batch specifications because through them, you can externalize the operations decoupled by the processes or other batch elements in other parts of your code. For example, you can write a listener that embraces more processes, and it starts after one particular operation of each process.

The following are the types of listeners we can write in WildFly. WildFly 10, through JBeret, supports three types of listeners, which we list in the following sections.