add validation constraints handling.

Author: hantsy

src/main/java/com/hantsylabs/restexample/springmvc/api/post/PostController.java

@@ -2,13 +2,15 @@
 
 import com.hantsylabs.restexample.springmvc.Constants;
 import com.hantsylabs.restexample.springmvc.domain.Post;
+import com.hantsylabs.restexample.springmvc.exception.InvalidRequestException;
 import com.hantsylabs.restexample.springmvc.model.CommentDetails;
 import com.hantsylabs.restexample.springmvc.model.CommentForm;
 import com.hantsylabs.restexample.springmvc.model.PostDetails;
 import com.hantsylabs.restexample.springmvc.model.PostForm;
 import com.hantsylabs.restexample.springmvc.model.ResponseMessage;
 import com.hantsylabs.restexample.springmvc.service.BlogService;
 import javax.inject.Inject;
+import javax.validation.Valid;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.data.domain.Page;
@@ -18,6 +20,7 @@
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.validation.BindingResult;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -87,9 +90,12 @@ public ResponseEntity<Page<CommentDetails>> getCommentsOfPost(
 
     @RequestMapping(value = "", method = RequestMethod.POST)
     @ResponseBody
-    public ResponseEntity<ResponseMessage> createPost(@RequestBody PostForm post) {
+    public ResponseEntity<ResponseMessage> createPost(@RequestBody @Valid PostForm post, BindingResult errResult) {
 
         log.debug("create a new post");
+        if (errResult.hasErrors()) {
+            throw new InvalidRequestException(errResult);
+        }
 
         PostDetails saved = blogService.savePost(post);