Need help with this project. I will include lecture notes to help guide and assist you. Please help me complete the java code needed to run this.

It is required to use Netbeans IDE and Derby databaseI met some NullPointerException bug but I dont know how to fix itI already finish most of the codeThis is the requirement for the assignment

case problem 2Carly's Catering provides meals for parties and special events. In previous chapters, you have developed a class that holds catering event information and an application that tests the methods using four objects of the class. Now modify the Event and EventDemo classes as follows:Modify the method that sets the event number in the Event class so that if the argument passed to the method is not a four-character String that starts with a letter followed by three digits, then the event number is forced to A000. If the initial letter in the event number is not uppercase, force it to be so.Add a contact phone number field to the Event class.Add a set method for the contact phone number field in the Event class. Whether the user enters all digits or any combination of digits, spaces, dashes, dots, or parentheses for a phone number, store it as all digits. For example, if the user enters (920) 872-9182, store the phone number as 9208729182. If the user enters a number with fewer or more than 10 digits, store the number as 0000000000.Add a get method for the phone number field. The get method returns the phone number as a String constructed as follows: parentheses surround a three-digit area code, followed by a space, followed by the three-digit phone exchange, followed by a hyphen, followed by the last four digits of the phone number.Modify the EventDemo program so that besides the event number and guests, the program also prompts the user for and retrieves a contact phone number for each of the sample objects. Display the phone number along with the other Event details. Test the EventDemo application to make sure it works correctly with valid and invalid event and phone numbers.Save the files as Event.java and EventDemo.java.case problem 1Sammy's Seashore Supplies rents beach equipment to tourists. In previous chapters, you have developed a class that holds equipment rental information and an application that tests the methods using four objects of the class. Now modify the Rental and RentalDemo classes as follows:Modify the method that sets the contract number in the Rental class so that if the argument passed to the method is not a four-character String that starts with a letter followed by three digits, then the contract number is forced to A000. If the initial letter in the contract number is not uppercase, force it to be so.Add a contact phone number field to the Rental class.Add a set method for the contact phone number field in the Rental class. Whether the user enters all digits or any combination of digits, spaces, dashes, dots, or parentheses for a phone number, store it as all digits. For example, if the user enters (920) 872-9182, store the phone number as 9208729182. If the user enters a number with fewer or more than 10 digits, store the number as 0000000000.Add a get method for the phone number field. The get method returns the phone number as a String constructed as follows: parentheses surround a three-digit area code, followed by a space, followed by the three-digit phone exchange, followed by a hyphen, followed by the last four digits of the phone number.Modify the RentalDemo program so that besides the contract number and minutes, the program also prompts the user for and retrieves a contact phone number for each of the sample objects. Display the phone number along with the other Rental details. Test the RentalDemo application to make sure it works correctly with valid and invalid contract and phone numbers.Save the files as Rental.java and RentalDemo.java.