about user defined exception in Java

User defined exceptions may be implemented by defining a new exception class by extending the Exception class.

public class MyException extends Exception {
/* class definition of constructors goes here */
public MyException() {
super();
}
public MyException (String errorMessage) {
super (errorMessage);
}
}
Throw and/or throws statement is used to signal the occurrence of an exception. Throw an exception:
throw new MyException(“I threw my own exception.”)
To declare an exception: public myMethod() throws MyException {…}