Spring Boot Starter Validation: getAllErrors vs getFieldErrors

Spring Boot Starter Validation is a powerful tool for validating data in your Spring Boot applications. It offers convenient annotations and utilities for enforcing data constraints. When using this starter for validation, you can use two methods, getAllErrors and getFieldErrors, to retrieve validation results.

The getAllErrors method returns all validation errors, including global errors and field errors. Conversely, the getFieldErrors method only returns field errors, excluding global errors.

Let's illustrate this with a simple example:

@RestController
@RequestMapping('/demo')
public class DemoController {

   @PostMapping('/test')
   public String test(@Validated DemoRequest request, BindingResult bindingResult) {
       if (bindingResult.hasErrors()) {
           List<ObjectError> allErrors = bindingResult.getAllErrors();
           List<FieldError> fieldErrors = bindingResult.getFieldErrors();
           // do something with errors
       }
       // handle request
   }

}

In this example, if the DemoRequest object has validation errors, bindingResult will contain these errors. You can use getAllErrors to retrieve all errors or getFieldErrors to get only field errors.

It's crucial to note that if the DemoRequest object has global errors, getAllErrors will return both global and field errors, while getFieldErrors will only return field errors. Therefore, choose the appropriate method for handling validation errors based on your specific needs.