An exception can be rethrown in a catch block. This action will cause the exception to be passed to the calling method. If the rethrow operation occurs in the main method then the exception is passed to the JVM and displayed on the console. The purpose of the rethrow operation is to get the attention of the outside world that an exception has occurred and at the same time perform any contingency logic (such as logging) in the catch block. To learn how to rethrow an exception in Java, follow these four steps.