mybatis報錯：Caused by: java.lang.IllegalArgumentException: Caches collection already contains value for com.crm.dao.PaperUserMapper

一、問題

    eclipse啟動時報下面的錯誤：

Caused by: java.lang.IllegalArgumentException: Caches collection already contains value for com.crm.dao.PaperUserMapper
    at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:782) ~[mybatis-3.2.7.jar:3.2.7]
    at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:754) ~[mybatis-3.2.7.jar:3.2.7]
    at org.apache.ibatis.session.Configuration.addCache(Configuration.java:516) ~[mybatis-3.2.7.jar:3.2.7]
    at org.apache.ibatis.builder.MapperBuilderAssistant.useNewCache(MapperBuilderAssistant.java:132) ~[mybatis-3.2.7.jar:3.2.7]
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.cacheElement(XMLMapperBuilder.java:209) ~[mybatis-3.2.7.jar:3.2.7]
    at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:114) ~[mybatis-3.2.7.jar:3.2.7]
    ... 82 common frames omitted

二、解決

    a.檢查命名空間、別名是否正確

    b.檢查mapper.xml和mapper.java中是否有重復的

    我這里是因為項目mapper.xml中出現重復的，修改后問題成功解決。小建議：把insert、select這些標簽折起來，然后看看id屬性是不是有重復的。

三、參考文獻

https://blog.csdn.net/prader/article/details/80547010

https://blog.csdn.net/zengdeqing2012/article/details/46340357