Adding validation to RequestParams

pom.xml

@@ -37,6 +37,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-thymeleaf</artifactId>
 		</dependency>
+		<dependency>
+		  <groupId>org.springframework.boot</groupId>
+		  <artifactId>spring-boot-starter-validation</artifactId>
+		</dependency>
 	</dependencies>
 
 	<build>

src/main/java/es/uv/garcosda/controllers/MeetupController.java

@@ -1,23 +1,35 @@
 package es.uv.garcosda.controllers;
 
 import es.uv.garcosda.domain.Meeting;
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.ConstraintViolationException;
+import jakarta.validation.constraints.NotEmpty;
+import jakarta.validation.constraints.NotNull;
 
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 import java.util.stream.Collectors;
 
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.servlet.view.RedirectView;
 
 @Controller
+@Validated
 public class MeetupController {
 	
 	DateTimeFormatter format = DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm");
@@ -39,7 +51,9 @@ public class MeetupController {
 	}
 	
 	@PostMapping("/")
-	public RedirectView addMeeting(Model model, @RequestParam("subject") String subject, @RequestParam("date") String date) {
+	public RedirectView addMeeting(Model model, @RequestParam("subject") @NotNull @NotEmpty String subject, 
+								   @RequestParam("date") @NotNull @NotEmpty @DateTimeFormat(pattern="dd/MM/yyyy hh:MM") String date) {
+		
 		meetings.add(new Meeting(subject, LocalDateTime.parse(date, this.format)));
 		model.addAttribute("meetings", this.meetings);
 		return new RedirectView("/");
@@ -51,4 +65,15 @@ public class MeetupController {
 		return new RedirectView("/");
 	}
 	
+	@ExceptionHandler(ConstraintViolationException.class)
+	@ResponseBody
+	public ResponseEntity<String> validationError(ConstraintViolationException ex) {
+		Set<ConstraintViolation<?>> violations = ex.getConstraintViolations();
+		String msg = "";
+		for(ConstraintViolation<?> v : violations) {
+			msg += v.getPropertyPath().toString() + " : " + v.getMessage() + ",  "; 
+		}
+	    return new ResponseEntity<String>(msg, HttpStatus.BAD_REQUEST);
+	}
+		
 }

src/main/java/es/uv/garcosda/domain/Meeting.java

@@ -4,10 +4,14 @@ import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.UUID;
 
+import org.springframework.format.annotation.DateTimeFormat;
+
+
 public class Meeting {
  
 	String id;
 	String subject;
+	@DateTimeFormat(pattern="dd/MM/yyyy hh:MM")
 	LocalDateTime date;
 	
 	public Meeting() {}

src/main/resources/templates/index.html

@@ -70,7 +70,7 @@
 						</div>
 						<div class="form-group">
 							<label>Date</label>
-							<input class="form-control" type="text" value="" name="date" placeholder="DD/MM/YYY HH:MM">
+							<input class="form-control" type="text" value="" name="date" placeholder="DD/MM/YYYY HH:MM">
 						</div>
 					</form>
 				</div>