message.properties

src/main/java/io/zipcoder/tc_spring_poll_application/dtos/error/ErrorDetail.java

     public void setErrors(Map<String, List<ValidationError>> errors) {
         this.errors = errors;
     }
+
+    public void setTimeStamp(long time) {
+    }
 }

src/main/java/io/zipcoder/tc_spring_poll_application/dtos/error/RestExceptionHandler.java

 package io.zipcoder.tc_spring_poll_application.dtos.error;
 import io.zipcoder.tc_spring_poll_application.exception.ResourceNotFoundException;
+import javafx.concurrent.Task;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.MessageSource;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 
 import javax.servlet.http.HttpServletRequest;
-import java.util.Date;
+import java.util.*;
 
 @ControllerAdvice
 public class RestExceptionHandler {
 
+    @Autowired
+    MessageSource messageSource;
+
     @ExceptionHandler(ResourceNotFoundException.class)
     public ResponseEntity<?> handleResourceNotFoundException(ResourceNotFoundException rnfe, HttpServletRequest request) {
         ErrorDetail errorDetail = new ErrorDetail();
 
         return new ResponseEntity<>(errorDetail, HttpStatus.NOT_FOUND);
     }
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<?>
+    handleValidationError(MethodArgumentNotValidException manve, HttpServletRequest request){
+        ErrorDetail ed = new ErrorDetail();
+
+        ed.setTimeStamp(new Date().getTime());
+        ed.setTitle("Validation Failure");
+        ed.setStatus(404);
+        ed.setDetail("Unable to complete request.");
+        ed.setDeveloperMessage(Arrays.toString(manve.getStackTrace()));
+
+
+        List<FieldError> fieldErrors =  manve.getBindingResult().getFieldErrors();
+        for(FieldError fe : fieldErrors) {
+
+            List<ValidationError> validationErrorList = ed.getErrors().computeIfAbsent(fe.getField(), k -> new ArrayList<>());
+            ValidationError validationError = new ValidationError();
+            validationError.setCode(fe.getCode());
+            validationError.setMessage(messageSource.getMessage(fe,null));
+            validationErrorList.add(validationError);
+        }
+
+        return new ResponseEntity<>(ed, HttpStatus.BAD_REQUEST);
+    }
 }

src/main/resources/message.properties

+NotEmpty.poll.question=Question is a required field
+Size.poll.options=Options must be greater than {2} and less than {1}