How to tackle 'illegalstateexception' in java?

The `IllegalStateException` is thrown when one tries to use a method at an inappropriate time, meaning the Java environment or application isn't in an appropriate state for the requested operation. Example:

ListIterator iterator = list.listIterator();

ListIterator iterator = list.listIterator();;
Ensure that methods are called in the correct sequence and the environment state is ready for the operation.

Beginner's Guide to Java