Pls code according to the description. And pls tidy your code - a snippet would be really appreciated and i will rate helpful right away for a correct answer.

Description Generating and catching exceptions Implement the methods validateAndAdd, add1, add2 and add3 in the manner described by the comments. QQ The validateAndAdd method should validate the given string according to the @throws clauses in the Javadoc, and throw the appropriate exceptions as necessary. The methods add1 through add3 should serve as "wrappers for the validateAndAdd method, and should use try-catch blocks to detect exceptions thrown by validateAndAdd according to each method's respective Javadoc.