<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="org.pojo.UesrinfoMapper"> <select id="froUser" parameterType="Integer" resultType="org.pojo.Uesrinfo"> select * from uesrinfo </select> <insert id="intoUser" parameterType="org.pojo.Uesrinfo"> insert into uesrinfo(username,password,boo) values (#{username},#{password},#{boo}) </insert> <update id="updtUser" parameterType="org.pojo.Uesrinfo"> update uesrinfo set username=#{username},password=#{password},boo=#{boo} where id=#{id} </update> <delete id="deltUser" parameterType="Integer"> delete from uesrinfo where order=#{id} </delete> </mapper>

你的 Mapper XML 文件中 namespace 属性值为 `org.pojo.UesrinfoMapper`，而不是 `org.pojo.UserinfoMapper`。请检查你的代码中是否有拼写错误，应该修改为正确的 Mapper 文件路径：`<mapper namespace="org.pojo.UesrinfoMapper">`。同时，你的 SQL 语句中的表名也有一个拼写错误，`uesrinfo` 应该是 `userinfo`。修改后的 Mapper XML 文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.pojo.UserinfoMapper">
  <select id="froUser" parameterType="Integer" resultType="org.pojo.Uesrinfo">
    select * from userinfo
  </select>
  <insert id="intoUser" parameterType="org.pojo.Uesrinfo">
    insert into userinfo(username,password,boo) values (#{username},#{password},#{boo})
  </insert>
  <update id="updtUser" parameterType="org.pojo.Uesrinfo">
    update userinfo set username=#{username},password=#{password},boo=#{boo} where id=#{id}
  </update>
  <delete id="deltUser" parameterType="Integer">
    delete from userinfo where id=#{id}
  </delete>
</mapper>

请注意检查 Mapper 文件路径和 SQL 语句是否都正确。