RESTful API Lab 4

Lab#4 Exception Handling –check if customer already exists

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The customers mobile phone number must be unique. In this lab we will check if a customer with the given phone number already exists and we will reject the request accordingly.

1. Add a package com.tus.accounts.exception with a class CustomerAlreadyExistsException

2. In the CustomerRepository interface add a query to find a Customer based on the mobile number. (This may be in your file already).

3. Now in the Service class add code that will throw the CustomerAlreadyExistsException.

4. Add a class in the exception package called GlobalExceptionHandler. This will handle exceptions in one location rather than duplicating the handlng. It is annotated with @ControllerAdvice and will handle the exception when thrown by the controller.

5. Test the application. Add a customer. Customer is created successfully. Then add a customer with the same mobile number again. The request is rejected with error message as shown.