diff --git a/Chapter3-1-7/src/main/java/com/didispace/Application.java b/Chapter3-1-7/src/main/java/com/didispace/Application.java
index b14e00c..7ac57d2 100755
--- a/Chapter3-1-7/src/main/java/com/didispace/Application.java
+++ b/Chapter3-1-7/src/main/java/com/didispace/Application.java
@@ -1,9 +1,11 @@
 package com.didispace;
 
-import com.didispace.dto.UserDto;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
@@ -11,6 +13,8 @@ import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RestController;
 
+import java.time.LocalDate;
+
 /**
  * @author 程序猿DD
  * @version 1.0.0
@@ -33,6 +37,16 @@ public class Application {
 
     }
 
+    @Data
+    @NoArgsConstructor
+    @AllArgsConstructor
+    static class UserDto {
+
+        private String userName;
+        private LocalDate birthday;
+
+    }
+
     @Bean
     public ObjectMapper serializingObjectMapper() {
         ObjectMapper objectMapper = new ObjectMapper();
diff --git a/Chapter3-1-7/src/main/java/com/didispace/dto/UserDto.java b/Chapter3-1-7/src/main/java/com/didispace/dto/UserDto.java
deleted file mode 100644
index 55b68af..0000000
--- a/Chapter3-1-7/src/main/java/com/didispace/dto/UserDto.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package com.didispace.dto;
-
-import lombok.AllArgsConstructor;
-import lombok.Data;
-import lombok.NoArgsConstructor;
-
-import java.time.LocalDate;
-
-@NoArgsConstructor
-@AllArgsConstructor
-@Data
-public class UserDto {
-
-    private String userName;
-    private LocalDate birthday;
-
-}
\ No newline at end of file