freemarker ,DEFAULT_INCOMPATIBLE_IMPROVEMENTS 找不到

一般出现这种问题的原因是，spring的版本和freemarker不匹配造成的~

nested exception is org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'freemarkEngine' defined in class path resource [conf/app-resources.xml]: Cannot resolve reference to bean 'freemarkerConfiguration' while setting bean property 'configuration'; 
nested exception is org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'freemarkerConfiguration' defined in class path resource [conf/app-resources.xml]: 
Invocation of init method failed; 
nested exception is java.lang.NoSuchFieldError: DEFAULT_INCOMPATIBLE_IMPROVEMENTS

版本不对。使用新版本： 
<!-- https://mvnrepository.com/artifact/org.freemarker/freemarker --> 
<dependency> 
<groupId>org.freemarker</groupId> 
<artifactId>freemarker</artifactId> 
<version>2.3.23</version> 
</dependency>

而不是： 
                <dependency> 
<groupId>freemarker</groupId> 
<artifactId>freemarker</artifactId> 
<version>2.3.9</version> 
</dependency>

参考链接：http://feng-tai-jun.iteye.com/blog/2331536