Result Maps collection already contains value for Mapper.BaseResultMap错误原因

完整的错误报告如下：

Caused by: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mapper.xxxMapper.BaseResultMap
 at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:578)
 at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:551)
 at org.apache.ibatis.session.Configuration.addResultMap(Configuration.java:356)
 at org.apache.ibatis.builder.MapperBuilderAssistant.addResultMap(MapperBuilderAssistant.java:138)
 at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement(XMLMapperBuilder.java:231)
 at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement(XMLMapperBuilder.java:201)
 at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElements(XMLMapperBuilder.java:196)
 at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:93)
 ... 8 more

这个错误原因很简单，我们的mapper.xml文件一般是mybatis-generator自动生成的，这种错误是因为我们在二次生成相同名字、相同位置的文件时，内容重复生成了。把重复的内容或者id名字删除就能解决这个错误。