3005 | updated custom constraint and test case

* Create MaxSizeConstraint.java

* Delete CustomConstraintValidator.java

* Delete CustomConstraint.java

* Create MaxSizeConstraintValidator.java

* Update MovieController.java

* Update MovieControllerIntegrationTest.java

spring-mvc-simple-2/src/main/java/com/baeldung/validation/listvalidation/constraint/MaxSizeConstraint.java

@@ -6,13 +6,13 @@ import java.lang.annotation.RetentionPolicy;
 import javax.validation.Constraint;
 import javax.validation.Payload;
 
-@Constraint(validatedBy = CustomConstraintValidator.class)
+@Constraint(validatedBy = MaxSizeConstraintValidator.class)
 @Retention(RetentionPolicy.RUNTIME)
-public @interface CustomConstraint {
-
-    String message() default "Movie name should start with an alphanumeric character.";
+public @interface MaxSizeConstraint {
 
+    String message() default "The input list cannot contain more than 4 movies.";
+    
     Class<?>[] groups() default {};
-
+    
     Class<? extends Payload>[] payload() default {};
 }

spring-mvc-simple-2/src/main/java/com/baeldung/validation/listvalidation/constraint/MaxSizeConstraintValidator.java

@@ -1,14 +1,13 @@
 package com.baeldung.validation.listvalidation.constraint;
 
 import java.util.List;
-import java.util.regex.Pattern;
 
 import javax.validation.ConstraintValidator;
 import javax.validation.ConstraintValidatorContext;
 
 import com.baeldung.validation.listvalidation.model.Movie;
 
-public class CustomConstraintValidator implements ConstraintValidator<CustomConstraint, List<Movie>> {
+public class MaxSizeConstraintValidator implements ConstraintValidator<MaxSizeConstraint, List<Movie>> {
 
     @Override
     public boolean isValid(List<Movie> values, ConstraintValidatorContext context) {
@@ -18,15 +17,10 @@ public class CustomConstraintValidator implements ConstraintValidator<CustomCons
             context.disableDefaultConstraintViolation();
             context.buildConstraintViolationWithTemplate("Movie list cannot be empty.")
                 .addConstraintViolation();
-        }
-        String regex = "[^A-Za-z0-9].*";
-        for (Movie movie : values) {
-            if (Pattern.matches(regex, movie.getName())) {
-                isValid = false;
-                break;
-            }
+        } else if (values.size() > 4) {
+            isValid = false;
         }
         return isValid;
     }
-
+    
 }

spring-mvc-simple-2/src/main/java/com/baeldung/validation/listvalidation/controller/MovieController.java

@@ -12,7 +12,7 @@ import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import com.baeldung.validation.listvalidation.constraint.CustomConstraint;
+import com.baeldung.validation.listvalidation.constraint.MaxSizeConstraint;
 import com.baeldung.validation.listvalidation.model.Movie;
 import com.baeldung.validation.listvalidation.service.MovieService;
 
@@ -25,7 +25,7 @@ public class MovieController {
     private MovieService movieService;
 
     @PostMapping
-    public void addAll(@RequestBody @NotEmpty(message = "Input movie list cannot be empty.") @CustomConstraint List<@Valid Movie> movie) {
-        movieService.addAll(movie);
+    public void addAll(@RequestBody @NotEmpty(message = "Input movie list cannot be empty.") @MaxSizeConstraint List<@Valid Movie> movies) {
+        movieService.addAll(movies);
     }
 }

spring-mvc-simple-2/src/test/java/com/baeldung/validation/listvalidation/MovieControllerIntegrationTest.java

@@ -61,11 +61,21 @@ public class MovieControllerIntegrationTest {
     }
     
     @Test
-    public void givenInvalidMovieName_whenAddingMovieList_thenThrowBadRequest() throws Exception {
-        Movie movie = new Movie("$Movie2");
+    public void given5MoviesInputList_whenAddingMovieList_thenThrowBadRequest() throws Exception {
+        Movie movie1 = new Movie("Movie1");
+        Movie movie2 = new Movie("Movie2");
+        Movie movie3 = new Movie("Movie3");
+        Movie movie4 = new Movie("Movie4");
+        Movie movie5 = new Movie("Movie5");
+        List<Movie> movies = new ArrayList<>();
+        movies.add(movie1);
+        movies.add(movie2);
+        movies.add(movie3);
+        movies.add(movie4);
+        movies.add(movie5);
         mvc.perform(MockMvcRequestBuilders.post("/movies")
             .contentType(MediaType.APPLICATION_JSON_UTF8)
-            .content(objectMapper.writeValueAsString(Arrays.asList(movie))))
+            .content(objectMapper.writeValueAsString(movies)))
             .andExpect(MockMvcResultMatchers.status()
                 .isBadRequest());
     }