Transactions should be on the root application context (or Hibernate will not be able to persist entities)

src/main/resources/spring/dao-config.xml

@@ -22,6 +22,8 @@
     <!-- import the dataSource definition -->
     <import resource="datasource-config.xml"/>
 
+    <context:component-scan
+            base-package="org.springframework.samples.petclinic.service"/>
 
     <!-- Configurer that replaces ${...} placeholders with values from a properties file -->
     <!-- (in this case, JDBC-related settings for the JPA EntityManager definition below) -->
@@ -40,7 +42,7 @@
     <!--
         Instruct Spring to perform declarative transaction management
         automatically on annotated classes.
-                
+
         for mode="aspectj"/ see SPR-6392
     -->
     <tx:annotation-driven/>

src/main/resources/spring/mvc-core-config.xml

@@ -20,7 +20,7 @@
         - POJOs labeled with the @Controller and @Service annotations are auto-detected.
     -->
     <context:component-scan
-            base-package="org.springframework.samples.petclinic.web, org.springframework.samples.petclinic.service"/>
+            base-package="org.springframework.samples.petclinic.web"/>
 
     <mvc:annotation-driven conversion-service="conversionService"/>