Feat: 공통 응답 추가

Author: dungbik

src/main/java/flipnote/user/global/error/ApiResponse.java

@@ -16,6 +16,13 @@ public class ApiResponse<T> {
     private final String message;
     private final T data;
 
+    public static <T> ApiResponse<T> success(T data) {
+        return ApiResponse.<T>builder()
+                .status(200)
+                .data(data)
+                .build();
+    }
+
     public static ApiResponse<Void> error(ErrorCode errorCode) {
         return ApiResponse.<Void>builder()
                 .status(errorCode.getStatus())

src/main/java/flipnote/user/global/error/ApiResponseAdvice.java

@@ -0,0 +1,31 @@
+package flipnote.user.global.error;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.server.ServerHttpRequest;
+import org.springframework.http.server.ServerHttpResponse;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
+
+@RestControllerAdvice(basePackages = "flipnote.user")
+public class ApiResponseAdvice implements ResponseBodyAdvice<Object> {
+
+    @Override
+    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
+        return !(returnType.getParameterType().isAssignableFrom(ApiResponse.class));
+    }
+
+    @Override
+    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
+                                  Class<? extends HttpMessageConverter<?>> selectedConverterType,
+                                  ServerHttpRequest request, ServerHttpResponse response) {
+        if (body == null) {
+            return null;
+        }
+        if (body instanceof ApiResponse<?>) {
+            return body;
+        }
+        return ApiResponse.success(body);
+    }
+}