Tukukkk

I have been unable to catch ConstraintViolationException (or DataIntegrityViolationException) in
ResponseEntityExceptionHandler.
I would like to return the jpa failure (e.g. which constraint violated) in the response.
(I prefer not to use @Valid on the method parameter and catch handleMethodArgumentNotValid).

...

import org.hibernate.exception.ConstraintViolationException;

import org.springframework.dao.DataIntegrityViolationException;



@ControllerAdvice

public class PstExceptionHandler extends ResponseEntityExceptionHandler {



    @ExceptionHandler({ConstraintViolationException.class})

    public ResponseEntity<Object> handleConstraintViolation(

        ConstraintViolationException ex, WebRequest request) {



        ...



        return new ResponseEntity<Object>(...);

    }

}



import javax.persistence.*;

import javax.validation.constraints.NotNull;

import javax.validation.constraints.Size;



@Entity

public class Student {



    @Id

    private Long id;



    @NotNull

    private String name;



    @NotNull

    @Size(min=7, message="Passport should have at least 7 characters")

    private String passportNumber;



    public Student() {

    }



...



}



@RequestMapping(value = "/addstudent"...)

@ResponseBody

public ResponseEntity<Object> addStudent(@RequestBody StudentDto studentDto) {



    Student student = new Student();

    student.setId(studentDto.getId());                          // 1L

    student.setName(studentDto.getName());                      // "helen"

    student.setPassportNumber(studentDto.getPassportNumber());  // "321"



    studentRepository.save(student);



    return ResponseEntity.accepted().body(student);

}

thank you...

Exceptions like ConstraintViolationException are not taken in account because they are extend from HibernateException. you can take a look exceptions in convert method that those are wrapped on Hibernate Exceptions.

@ExceptionHandler({TransactionSystemException.class})

public ResponseEntity<Object> handleConstraintViolation(TransactionSystemException ex, WebRequest request) {



    if (ex.getCause() instanceof RollbackException) {

       RollbackException rollbackException = (RollbackException) ex.getCause();

         if (rollbackException.getCause() instanceof ConstraintViolationException) {

             return new ResponseEntity<Object>(...);

         }

    ...

    }

    ...



    return new ResponseEntity<Object>(...);

}

There're 3 ways:

1. 
   

   @Valid @Validated annotations.

   
   
   

   Once they used at parameter level, violations are available via method-injected Errors BindingResult type implementations.

   
   



2. ConstraintViolationException is thrown each time an entity in non-valid state is passed to .save() or .persist() Hibernate methods.




3. Entities may be manually validated via injected LocalValidatorFactoryBean.validate() method. The constraint violations then available through passed Errors object's implementation.
   Exactly, how @Valid @Validated annotations are internally implemented.