springboot_validation : MessageCodesResolver

springboot_validation/src/main/resources/errors.properties

@@ -2,3 +2,6 @@ required.item.itemName=상품 이름은 필수입니다.
 range.item.price=가격은 {0} ~ {1} 까지 허용합니다.
 max.item.quantity=수량은 최대 {0} 까지 허용합니다.
 totalPriceMin=가격 * 수량의 합은 {0}원 이상이어야 합니다. 현재 값 = {1}
+
+
+required=필수 값 입니다.

springboot_validation/src/test/java/hello/itemservice/validation/MessageCodesResolverTest.java

@@ -0,0 +1,37 @@
+package hello.itemservice.validation;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.validation.DefaultMessageCodesResolver;
+import org.springframework.validation.MessageCodesResolver;
+import org.springframework.validation.ObjectError;
+
+import static org.assertj.core.api.Assertions.*;
+
+public class MessageCodesResolverTest {
+
+    MessageCodesResolver codesResolver = new DefaultMessageCodesResolver();
+
+    @Test
+    void messageCodesResolverObject() {
+        String[] messageCodes = codesResolver.resolveMessageCodes("required", "item");
+        for (String messageCode : messageCodes) {
+            System.out.println("messageCode = " + messageCode);
+        }
+        assertThat(messageCodes).containsExactly("required.item", "required");
+    }
+
+    @Test
+    void messageCodesResolverField() {
+        String[] messageCodes = codesResolver.resolveMessageCodes("required", "item", "itemName", String.class);
+        for (String messageCode : messageCodes) {
+            System.out.println("messageCode = " + messageCode);
+        }
+        assertThat(messageCodes).containsExactly(
+                "required.item.itemName",
+                "required.itemName",
+                "required.java.lang.String",
+                "required"
+        );
+    }
+}