springMVC整合mybatis

[梦灯]

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [com/meng/source/applicationContext.xml]: Invocation of init method failed; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'class path resource [com/meng/mapper/User.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 42; 文档根元素 "mapper" 必须匹配 DOCTYPE 根 "null"。

谁能帮忙解决一下吗？谢谢。