You have to use at least version 3.2.8.RELEASE
of spring-core.
For Maven, set in your pom.xml
:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>3.2.8.RELEASE</version>
</dependency>
Source: http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/cglib/core/SpringNamingPolicy.html, since 3.2.8.