own exception java code example

Example 1: how to make a custom exception in java

public class CustomException extends Exception { 
    public CustomException(String errorMessage) {
        super(errorMessage);
    }
}

Example 2: exception java

1.Unchecked: occurs during run time
2.Checked Exceptions:occurs during the compile time. 
needs to be handled IMMEDIATELY
Exception handling: try & catch: blocks, used for handling the exception 
 
throws keyword is used within the method signature 
disadvantage is: throws keyword whoever calls the method 
will have to handle the exception again but with 
try/catch you handle once. Try/catch is better way to handle it 
in utility class. Next time you call method you don’t get any exceptions
 
most common Exception like NullPointerExceptio, 
ArrayIndexOutOfBound, ClassNotFoundException, IOException.
are unchecked and they are descended from java.lang.RuntimeException
In Selenium: nosuchelement, nostaleexception, nosuchaframe 
In SQL: SQL exception