Fix #89 Web layer: use @Valid whenever possible

src/main/java/org/springframework/samples/petclinic/web/PetController.java

@@ -34,6 +34,8 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.SessionAttributes;
 import org.springframework.web.bind.support.SessionStatus;
 
+import javax.validation.Valid;
+
 /**
  * @author Juergen Hoeller
  * @author Ken Krebs
@@ -57,8 +59,9 @@ public class PetController {
     }
 
     @InitBinder
-    public void setAllowedFields(WebDataBinder dataBinder) {
+    public void initBinder(WebDataBinder dataBinder) {
         dataBinder.setDisallowedFields("id");
+        dataBinder.setValidator(new PetValidator());
     }
 
     @RequestMapping(value = "/owners/{ownerId}/pets/new", method = RequestMethod.GET)
@@ -71,8 +74,7 @@ public class PetController {
     }
 
     @RequestMapping(value = "/owners/{ownerId}/pets/new", method = RequestMethod.POST)
-    public String processCreationForm(@ModelAttribute("pet") Pet pet, BindingResult result, SessionStatus status) {
-        new PetValidator().validate(pet, result);
+    public String processCreationForm(@Valid Pet pet, BindingResult result, SessionStatus status) {
         if (result.hasErrors()) {
             return "pets/createOrUpdatePetForm";
         } else {
@@ -90,9 +92,7 @@ public class PetController {
     }
 
     @RequestMapping(value = "/owners/{ownerId}/pets/{petId}/edit", method = {RequestMethod.PUT, RequestMethod.POST})
-    public String processUpdateForm(@ModelAttribute("pet") Pet pet, BindingResult result, SessionStatus status) {
-        // we're not using @Valid annotation here because it is easier to define such validation rule in Java
-        new PetValidator().validate(pet, result);
+    public String processUpdateForm(@Valid Pet pet, BindingResult result, SessionStatus status) {
         if (result.hasErrors()) {
             return "pets/createOrUpdatePetForm";
         } else {

src/main/java/org/springframework/samples/petclinic/web/PetValidator.java

@@ -18,16 +18,22 @@ package org.springframework.samples.petclinic.web;
 import org.springframework.samples.petclinic.model.Pet;
 import org.springframework.util.StringUtils;
 import org.springframework.validation.Errors;
+import org.springframework.validation.Validator;
 
 /**
  * <code>Validator</code> for <code>Pet</code> forms.
+ * <p>
+ * We're not using Bean Validation annotations here because it is easier to define such validation rule in Java.
+ * </p>
  *
  * @author Ken Krebs
  * @author Juergen Hoeller
  */
-public class PetValidator {
+public class PetValidator implements Validator {
 
-    public void validate(Pet pet, Errors errors) {
+    @Override
+    public void validate(Object obj, Errors errors) {
+        Pet pet = (Pet) obj;
         String name = pet.getName();
         // name validation
         if (!StringUtils.hasLength(name)) {
@@ -47,4 +53,13 @@ public class PetValidator {
         }
     }
 
+    /**
+     * This Validator validates *just* Pet instances
+     */
+    @Override
+    public boolean supports(Class<?> clazz) {
+        return Pet.class.equals(clazz);
+    }
+
+
 }