这个错在那啊？？？？？？

1.网上的都试了
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.bjsxt.mapper.UsersMapper.selectUsersAll] with root cause

UsersMapper.xml

<?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="com.bjsxt.mapper">
    <resultMap id="BaseResultMap" type=" com.bjsxt.pojo.Users">
        <result column="id" property="id"></result>
        <result column="name" property="name"></result>
        <result column="age" property="age"></result>
    </resultMap>
<!--    <insert id="insertUser" parameterType="com.bjsxt.pojo.Users">-->
<!--        insert into users(id,name,age,password) values(#{id},#{name},#{age},#{password})-->
<!--    </insert>-->
    <select id="selectUsersAll"  resultMap="BaseResultMap">
         select * from user
     </select>
</mapper>

UserMapper.java

package com.bjsxt.mapper;

import com.bjsxt.pojo.Users;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;
@Mapper
public interface UsersMapper {
    void insertUser(Users users);
    List<Users> selectUsersAll();


}

看看你的mapper文件，

<mapper namespace="com.bjsxt.mapper">

只指定到了你dao的包的位置，而没有指定到具体对应的dao接口，
应该这样写

<mapper namespace="com.bjsxt.mapper.UsersMapper">

建议先多了解一下spring集成mybatis的文档说明，再开始写代码

按照楼上的改了，然后检查表名是user还是users

检查一下 UserMapper 接口类看看有没有定义 selectUsersAll 接口方法。