solve: **Understanding and Implementing Custom Exceptions in Java**In a particular business, all documents are designated by one-character codes that indicate their classification: - **U** for Unclassified- **C** for Confidential- **P** for ProprietaryThese codes are prefixes for file names, preceded by an underscore. Example file names include `U_QuarterOneData.txt` or `P_Numbers.txt`.### TaskThe goal is to create an exception class called `InvalidDocumentCodeException`. This custom exception will be triggered when a document's designation does not match U, C, or P.### Implementation- **Driver Class**: Implement this exception in a Driver class that reads file names from the user.- When the program finds a file with an invalid code, it raises `InvalidDocumentCodeException`.- Catch this exception, output "This document has an invalid code.", and continue processing the remaining files.- The program terminates when the user inputs "DONE".### Example Execution**Sample Run #1:** Execution of the program```plaintextjava DriverEnter: file:name:U_JuneData.txtEnter: file:name:P_JulyData.txtEnter: file:name:C_AugustData.txtEnter: file:name:K_SeptemberData.txtThis document has an invalid code.Enter: file:name:C_OctoberData.txtEnter: file:name:DONE```### ExplanationThe sample run demonstrates entering multiple file names. When a file name starting with an invalid designation ('K_SeptemberData.txt' here, which starts with 'K') is detected, it triggers the exception and prints the error message. The program continues to request file names until "DONE" is entered, at which point it stops processing.This exercise is designed to emphasize the utility and implementation of custom exceptions to handle specific cases in Java programming.

Solution- The provided Java code requests the user's input on the file names. Code- import java.util.*;class InvalidDocumentCodeException extends Exception{//Function decLare class of exception public InvalidDocumentCodeException(String s){super(s);}}public class Main{//main classpublic static void main (String[] args) {Scanner in=new Scanner(System.in);//defining a ScaNner Class to read StringString s;while(true)//condition checking{try{System.out.print("Enter a string:");s=in.nextLine();//function that read string after //initialize its done then this function exist in nExt lineif(s.equals("DONE")) break;else if(s.charAt(0)=='U' || s.charAt(0)=='C' || s.charAt(0)=='P')//initialize The if else conditioncontinue;elsethrow new InvalidDocumentCodeException("This document has an invalid code");//function to declare an invalid code message}catch(InvalidDocumentCodeException e){//Function that Declares CaTch ExceptionSystem.out.println(e.getMessage());//function to get message}}}}Running code Output-