Creating user defined or custom exception in java

Creating custom or user defined exception

                Java allows us to write own exception class for our project, we all know that all exceptions are subclasses of Exception

Writing custom unchecked Exception

                To create a unchecked exception, make your exception call to be a subclass of RuntimeException

Example

public class UserException extends RuntimeException {

		public UserException() {
			// TODO Auto-generated constructor stub
			super("User Exception Invaild User");
		}

	}

You can write your own condition when this exception should occur

public class UserProcess {

		void register(String name)
	      {
	            if(....) // verify the user and throw custom Exception
	            {
	                  throw new UserException();
	            }
	      }
	}

Writing custom checked Exception

                To create a unchecked exception, make your exception call to be a subclass of Exception

Example

public class UserException extends Exception {

		public UserException() {
			// TODO Auto-generated constructor stub
			super("User Exception Invaild User");
		}

	}

public class UserProcess {

	void register(String name)
	{
	    if(....) // verify the user and throw custom Exception
	     {
	          throw new UserException();
	     }
	 }
}

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