Change identifier and add error message in properties file

Signed-off-by: Sukhminder Arora <sukhminderarora@gmail.com>

src/main/java/org/springframework/samples/petclinic/model/Person.java

@@ -28,11 +28,11 @@ import jakarta.validation.constraints.NotBlank;
 public class Person extends BaseEntity {
 
 	@Column(name = "first_name")
-	@NotBlank(message = "First name is required")
+	@NotBlank(message = "{person.firstName.required}")
 	private String firstName;
 
 	@Column(name = "last_name")
-	@NotBlank(message = "Last name is required")
+	@NotBlank(message = "{person.lastName.required}")
 	private String lastName;
 
 	public String getFirstName() {

src/main/java/org/springframework/samples/petclinic/owner/OwnerController.java

@@ -47,7 +47,8 @@ import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 class OwnerController {
 
 	private static final String VIEWS_OWNER_CREATE_OR_UPDATE_FORM = "owners/createOrUpdateOwnerForm";
-	public static final String REDIRECT_OWNERS = "redirect:/owners/";
+
+	private static final String REDIRECT_OWNERS = "redirect:/owners/";
 
 	private final OwnerRepository owners;
 

src/main/resources/messages/messages.properties

@@ -6,3 +6,6 @@ nonNumeric=must be all numeric
 duplicateFormSubmission=Duplicate form submission is not allowed
 typeMismatch.date=invalid date
 typeMismatch.birthDate=invalid date
+person.lastName.required=Last name is required
+person.firstName.required=Last name is required
+