Implementation of category creation.

codiki-application/src/main/java/org/codiki/application/category/CategoryCreationValidator.java

@@ -0,0 +1,7 @@
+package org.codiki.application.category;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class CategoryCreationValidator {
+}

codiki-application/src/main/java/org/codiki/application/category/CategoryUseCases.java

@@ -1,8 +1,13 @@
 package org.codiki.application.category;
 
+import static java.util.Collections.emptyList;
+import static java.util.Objects.isNull;
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 
+import static org.codiki.domain.category.model.builder.CategoryBuilder.aCategory;
+import org.codiki.domain.category.exception.CategoryEditionException;
 import org.codiki.domain.category.model.Category;
 import org.codiki.domain.category.port.CategoryPort;
 import org.springframework.stereotype.Service;
@@ -18,4 +23,25 @@ public class CategoryUseCases {
     public Optional<Category> findById(UUID categoryId) {
         return categoryPort.findById(categoryId);
     }
+
+    public Category createCategory(String name, List<UUID> subCategoryIds) {
+        if (isNull(name)) {
+            throw new CategoryEditionException("name can not be empty");
+        }
+
+        List<Category> subCategories = emptyList();
+        if (!isNull(subCategoryIds)) {
+            subCategories = categoryPort.findAllByIds(subCategoryIds);
+        }
+
+        Category newCategory = aCategory()
+            .withId(UUID.randomUUID())
+            .withName(name)
+            .withSubCategories(subCategories)
+            .build();
+
+        categoryPort.save(newCategory);
+
+        return newCategory;
+    }
 }