BindingException异常：Type interface com.niuyun.dao.UserDao is not known to the MapperRegistry.解决了-526互联

Mybatis出现：`org.apache.ibatis.binding.BindingException: Type interface com.niuyun.dao.UserDao is not known to the MapperRegistry.`的错误，如何解决？

错误如下：

类型接口dao不知道mapper注册中心点的问题

org.apache.ibatis.binding.BindingException: Type interface com.niuyun.dao.UserDao is not known to the MapperRegistry.
	at org.apache.ibatis.binding.MapperRegistry.getMapper(MapperRegistry.java:47)
	at org.apache.ibatis.session.Configuration.getMapper(Configuration.java:745)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.getMapper(DefaultSqlSession.java:292)
	at com.haroro.test.AccountTest.init(AccountTest.java:40)

! 很明显是没有注册映射的路径

查看MyBatis中xml配置文件，其中系统的核心设置

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
 
</configuration>

发现确实少了映射的路径配置，将其加上

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
 
   <!--映射的路径-->
  <mappers>
    <mapper resource="org/mybatis/example/BlogMapper.xml"/>
  </mappers>
</configuration>

如果改正后还是出现同样的问题，那么要去看映射路径的.xml文件，其中查看"namespace"的类名是否正确，不正确就改正

<!--名字命名空间--><!--如果使用的是mapper接口的形式， 则namespace 写的就是接口的全类名-->
<mapper namespace="com.qianfeng.dao.UserDao">

<!--resultType   返回值的结果的类型--><!--#{id}  占位符，相当于 ？-->
    <select id="getOne" resultType="com.qianfeng.entity.User">

        select * from user where id = #{id}

    </select>
</mapper>