Server-Side Validations and Spring Boot Testing

1. Server-Side Validations

Layers for Validation

• Presentation Logic (P.L)
  • To be performed in Rest Controller
• Business Logic (B.L)
  • In service layer

Development Steps for Adding Server-Side P.L Validations

1. Add Dependency
   • Add spring boot validation starter dependency
     • pom.xml (done already in spring boot backend template)
2. Validate Request Body
   • Add @Valid annotation along with @RequestBody (de-serial)
   • Add validation rules (annotations - jakarta, spring , hibernate-validator) on DTO fields.
     • eg - @NotNull , @NotEmpty , @NotBlank , @Email , @Pattern, @Length,@Min , @Max , @Future ,@Past, @DateTimeFormat ....
   • More details -
     • @NotEmpty
       • =>Strings cannot be null and must have at least one character including whitespace
       • for collections must contain at least 1 element
     • @NotBlank
       • strings not null n must contain some content after whitespace trimming
     • @NotNull
       • => simply not null (use it typically on non string fields - eg LocalDate , enum , double ...)
   • In case of P.L failure , Spring throws
     • MethodArgumentNotValidException
   • add new exception handler method(@ExceptionHandler) in global exception handler class(@RestControllerAdvice)
3. Validate PathVariable or Request Parameter
   • Add @Validated annotation
     • on rest controller class
     • use same validation annotations with @RequestParam | @PathVariable
     • In case of P.L failure , Spring throws
       • ConstraintViolationException

3.1 User Signup Endpoint

• Add it for User sign up end point n test.

2. Spring Boot Testing

• Unit Testing
• Integration Testing

Task: Add Unit Test for Data Layer

• Methods to Test:
  • getRestaurantAndMenu(Long id);
  • findTop3ByUserRoleOrderBySubscriptionAmountDesc(UserRole role);
• Write in DAO Layer:
  • Get list of user’s last name from specified city
    • Input - city
  • Write its test case

3. Spring AOP

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