[FIXED] How catch hibernate/jpa constraint violations in Spring Boot?

Issue

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...

Solution

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.

Answered By - WildDev