This is Online Banking System The objective of this project is to maintain the accounts like saving account,. Here Accountant can do the all operations Like close the Account open the account and Customer do the required operations like he/she can register himself/herself, can view balance and deposit ,transfer and withdrawal.
Use @DaTa annotations from lombok package for dynamic getters and setters , won't have to create getters and setters manually for all the parameters in entity classes.
Instead of prepared statements in DAO implementations , you could use JPA (Java persistence API) , it gives more flexibility in terms of querying the db.
It provides methods such as findById() where you won't have to write native sql queries explicitly.
Internally JPA uses prepared statements only , so it does the job of creating the corresponding queries for you.
good job on separating the DB Util class . [nit] => always close the conn object that you open.
conn object could have been globalized or passed as a reference .
In jpa , no need to create conn objects , it does the job for us . pasting some links for JPA
put Use cases classes in service layer where all the business logic must reside.
separate controller , service layer must be present .
could remove DBUtil from utility into configuration package and initialize the conn objects using dependency injection. Pasting some useful links for dependency injections below.