Unraveling the Secrets of PropertyBatchUpdateException in Spring Framework

Greetings Spring enthusiasts! Have you encountered a PropertyBatchUpdateException while working with the Spring framework? If yes, then this post is just what you need. We will cover the nitty-gritty of PropertyBatchUpdateException, its causes and solution, and wrap it up with some code examples to bring the concept into perspective.

What is PropertyBatchUpdateException?

In the Spring framework, PropertyBatchUpdateException is an exception class that is used to collect and hold individual PropertyAccessExceptions. This exception is thrown when multiple errors are encountered during the property update process via data binding.

Causes of PropertyBatchUpdateException

PropertyBatchUpdateException mainly occurs while processing form submissions in a Spring MVC or Spring WebFlux application. When the form fields are bound to the properties of a Java Bean, and if any binding-related errors occur, the framework encapsulates all these errors into PropertyBatchUpdateException. These errors can vary, from type mismatch to missing fields or validation issues.

Take a look at this code snippet:

@Data
public class User {
    private String name;
    private String email;
    private int age;
}

Now, suppose we are trying to bind an incoming request to this User object, and the request payload somehow does not match the User fields. Let’s say the age field is not in an int format or the email field is not present in the payload. These discrepancies will result in one or more PropertyAccessExceptions, which collectively form a PropertyBatchUpdateException.

Handling PropertyBatchUpdateException

Now, how do we efficiently handle these exceptions? A simple way is to use validation annotations from JSR 303 Bean Validation API. Let’s modify our User model and add some validations.

import javax.validation.constraints.Email;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotBlank;

@Data
public class User {
    @NotBlank
    private String name;
    
    @Email
    @NotBlank
    private String email;
    
    @Min(18)
    private int age;
}

In the controller, we can use @Valid annotation to enforce these validations when binding data to JavaBean.

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;

@RestController
@RequestMapping("/users")
public class UserController {
    @PostMapping
    public ResponseEntity<String> createUser(@Valid @RequestBody User user){
         // Code to save user.
         return new ResponseEntity<>(HttpStatus.CREATED);
    }
    
    @InitBinder
    public void initBinder(WebDataBinder binder){
        binder.setDisallowedFields("id");
    }
}

In the above code, @InitBinder is used to prevent the user from updating the id field. If an attempt is made to update id, it will result in PropertyAccessException which might eventually lead to PropertyBatchUpdateException if multiple such errors occur.

Next, we need to handle the MethodArgumentNotValidException thrown due to validation failure.

@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<String> handleValidationExceptions(
            MethodArgumentNotValidException ex){
        // Exception handling logic
    }
}

With the combination of Spring’s web request binding and JSR 303 Bean Validation, you can manage a significant part of the data binding errors, including PropertyBatchUpdateException.

Refer to the official Spring documentation here and here for a more detailed grasp on PropertyBatchUpdateException and how @InitBinder works.