Mybatis基础问题---resultType=hashmap有何特殊？

weidu23 2014-01-17 09:34:00
首先说明，我这个是springh+mybatis的东西。
我在java里面有一个model包，里面的类叫UserInf，定义如下：
package zxw.model;

public class UserInf {

    private Integer userId;

    private String userName;

    private String userPasswd;

    //getter and setter

}

此时，我在mybatis的UserInfMapper.xml中写道：
<mapper namespace="zxw.dao.UserInfMapper" >

  	<!-- public UserInf selectPublicName(String userName); -->

  	<select id="obtainedPublicName" resultType="zxw.model.UserInf" parameterType="java.lang.String">

  	select * from userInf where user_name = #{userName,jdbcType=VARCHAR}

  </select>

</mapper>

其中，对应的UserIntMapper.java中写了


package zxw.dao;

import zxw.model.UserInf;

public interface UserInfMapper {

    /**根据名字查询数据*/

    UserInf obtainedPublicName(String userName);

}

然后在service层中一个被@Service("user")的类中定义bean。
最后是调用getBean获取数据！


	public static boolean checkUser(String userName , String userPasswd){

		UserInfServiceI userInf = (UserInfServiceImpl)CreateBean.beanFactory("userInfService");

		System.out.println(userInf.maxId());

		UserInf user = userInf.findByName(userName);

		System.out.println(user);

		if( null == user )

			return false ;

		return  (

					! user.getUserName().equals(userName)

					||

					! user.getUserPasswd().equals(userPasswd)

				)

				?

				false

				:

				true;

	}


此时，发现System.out.println(user);输入为null !!!

于是，我做了几个测试，我发现了：
我把UserInfMapper.xml中的resultType="zxw.model.UserInf" 改成resultType="hashmap"，
我就能 System.out.println(user);打印出user信息了！！！
-----------------------
问：
为什么我自己定义的resultType返回值类型就不能获取数据库信息，而resultType为hashmap就可以？
可是，我的zxw.model.UserInf存在啊？？？
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陌乐 2016-06-26
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你好，你调用方法为什么会用findbyname 而不是这个方法obtainedPublicName？
weidu23 2014-01-17
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引用 2 楼 leox_2012 的回复:
<resultMap id="BaseResultMap" type="cn.caculate.model.CalData" >
    <id column="cal_data_id" property="calDataId" jdbcType="INTEGER" />
    <result column="prjid" property="prjid" jdbcType="INTEGER" />
    <result column="data_file_id" property="dataFileId" jdbcType="INTEGER" />
    <result column="data_type" property="dataType" jdbcType="INTEGER" />
  </resultMap>
你先将你自己的实体对象映射成一个resultMap，然后在查询的select里面使用resultMap参数对其进行引用。如下： 
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from cal_data
    where cal_data_id = #{calDataId,jdbcType=INTEGER}
  </select>
的确是这样的， 通过看你的、还有楼上的xml代码， 我倒是知道自己错在哪里了！ 谢谢你 也谢谢楼上
weidu23 2014-01-17
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引用 4 楼 xieyongcx 的回复:
<?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="ShopCarMapper">
	<sql id="notDeletedSql"> is_deleted = 0 </sql> 
	<sql id="isDeletedSql"> is_deleted = 1 </sql> 
  <resultMap id="ShopCar" type="com.able.mycu.model.course.ShopCar">
		<result property="shopCarId" column="SHOP_CAR_ID" />
		<result property="recruitId" column="RECRUIT_ID" />
		<result property="number" column="NUMBER" />
		<result property="courseId" column="COURSE_ID" />
		<result property="mode" column="MODE" />
		<result property="importMoney" column="IMPORT_MONEY" />
		<result property="courseName" column="COURSE_NAME" />
		<result property="isDeleted" column="IS_DELETED" />
		<result property="updateAt" column="UPDATE_AT" />
		<result property="createAt" column="CREATE_AT" />
  </resultMap>

	<select id="getShopCarById" parameterType="int" resultMap="ShopCar">
		select * from TBL_SHOP_CAR where shop_car_id = #{shopCarId} and <include refid="notDeletedSql"/>

	</select>
	
	<select id="listShopCar" parameterType="com.able.mycu.search.course.ShopCarSearch" resultMap="ShopCar">
	    select * from TBL_SHOP_CAR where <include refid="notDeletedSql"/>
<!--		<if test="shopCarId != null"> and SHOP_CAR_ID = #{shopCarId} </if>	-->
<!--		<if test="recruitId != null"> and RECRUIT_ID = #{recruitId} </if>	-->
<!--		<if test="number != null"> and NUMBER = #{number} </if>	-->
<!--		<if test="courseId != null"> and COURSE_ID = #{courseId} </if>	-->
<!--		<if test="mode != null"> and MODE = #{mode} </if>	-->
<!--		<if test="importMoney != null"> and IMPORT_MONEY = #{importMoney} </if>	-->
<!--		<if test="courseName != null"> and COURSE_NAME like CONCAT('%','${COURSE_NAME}','%') </if>			-->
<!--		<if test="isDeleted != null"> and IS_DELETED like CONCAT('%','${IS_DELETED}','%') </if>			-->
<!--		<if test="updateAt != null"> and UPDATE_AT = #{updateAt} </if>	-->
<!--		<if test="createAt != null"> and CREATE_AT like CONCAT('%','${CREATE_AT}','%') </if>			-->
			<if test="schoolId != null"> and SCHOOL_ID=#{schoolId} </if>
			<if test="userId != null"> and USER_ID=#{userId} </if>			
	limit #{start},#{limit}
	</select>
	
	<select id="countShopCar" parameterType="com.able.mycu.search.course.ShopCarSearch" resultType="int">
		select count(1) from TBL_SHOP_CAR where <include refid="notDeletedSql"/>
<!--		<if test="shopCarId != null"> and SHOP_CAR_ID = #{shopCarId} </if>	-->
<!--		<if test="recruitId != null"> and RECRUIT_ID = #{recruitId} </if>	-->
<!--		<if test="number != null"> and NUMBER = #{number} </if>	-->
<!--		<if test="courseId != null"> and COURSE_ID = #{courseId} </if>	-->
<!--		<if test="mode != null"> and MODE = #{mode} </if>	-->
<!--		<if test="importMoney != null"> and IMPORT_MONEY = #{importMoney} </if>	-->
<!--		<if test="courseName != null"> and COURSE_NAME like CONCAT('%','${COURSE_NAME}','%') </if>			-->
<!--		<if test="isDeleted != null"> and IS_DELETED like CONCAT('%','${IS_DELETED}','%') </if>			-->
<!--		<if test="updateAt != null"> and UPDATE_AT = #{updateAt} </if>	-->
<!--		<if test="createAt != null"> and CREATE_AT like CONCAT('%','${CREATE_AT}','%') </if>			-->
	</select>
	
	<select id="listAllShopCar" parameterType="com.able.mycu.search.course.ShopCarSearch" resultMap="ShopCar">
	    select * from TBL_SHOP_CAR where <include refid="notDeletedSql"/>
<!--		<if test="shopCarId != null"> and SHOP_CAR_ID = #{shopCarId} </if>	-->
<!--		<if test="recruitId != null"> and RECRUIT_ID = #{recruitId} </if>	-->
<!--		<if test="number != null"> and NUMBER = #{number} </if>	-->
<!--		<if test="courseId != null"> and COURSE_ID = #{courseId} </if>	-->
<!--		<if test="mode != null"> and MODE = #{mode} </if>	-->
<!--		<if test="importMoney != null"> and IMPORT_MONEY = #{importMoney} </if>	-->
<!--		<if test="courseName != null"> and COURSE_NAME like CONCAT('%','${COURSE_NAME}','%') </if>			-->
<!--		<if test="isDeleted != null"> and IS_DELETED like CONCAT('%','${IS_DELETED}','%') </if>			-->
<!--		<if test="updateAt != null"> and UPDATE_AT = #{updateAt} </if>	-->
<!--		<if test="createAt != null"> and CREATE_AT like CONCAT('%','${CREATE_AT}','%') </if>			-->
			<if test="schoolId != null"> and SCHOOL_ID=#{schoolId} </if>
			<if test="userId != null"> and USER_ID=#{userId} </if>	
	</select>

	<insert id="saveShopCar" parameterType="com.able.mycu.model.course.ShopCar">
		insert into TBL_SHOP_CAR (
			<if test="recruitId != null"> RECRUIT_ID </if>
			<if test="number != null"> ,NUMBER </if>
			<if test="courseId != null"> ,COURSE_ID </if>
			<if test="mode != null"> ,MODE </if>
			<if test="importMoney != null"> ,IMPORT_MONEY </if>
			<if test="courseName != null"> ,COURSE_NAME </if>
			<if test="isDeleted != null"> ,IS_DELETED </if>
			<if test="updateAt != null"> ,UPDATE_AT </if>
			<if test="createAt != null"> ,CREATE_AT </if>
			<if test="userId != null"> ,USER_ID </if>
			<if test="schoolId != null"> ,SCHOOL_ID </if>
		)
		values (
		<if test="recruitId != null"> #{recruitId} </if>
		<if test="number != null"> ,#{number} </if>
		<if test="courseId != null"> ,#{courseId} </if>
		<if test="mode != null"> ,#{mode} </if>
		<if test="importMoney != null"> ,#{importMoney} </if>
		<if test="courseName != null"> ,#{courseName} </if>
		<if test="isDeleted != null"> ,#{isDeleted} </if>
		<if test="updateAt != null"> ,#{updateAt} </if>
		<if test="createAt != null"> ,#{createAt} </if>
		<if test="userId != null"> ,#{userId} </if>
		<if test="schoolId != null"> ,#{schoolId} </if>
		)
	<selectKey resultType="int" order="AFTER" keyProperty="shopCarId">
		SELECT LAST_INSERT_ID() AS shop_car_id
	</selectKey>
	</insert>

	<update id="removeShopCarByRecruitId" parameterType="hashmap" >
		delete from TBL_SHOP_CAR where RECRUIT_ID = #{recruitId} and USER_ID=#{userId} and schoolId =#{schoolId}
	</update>

	<update id="updateShopCarById" parameterType="com.able.mycu.model.course.ShopCar">
		update TBL_SHOP_CAR set 
<!--		<if test="shopCarId != null"> ,SHOP_CAR_ID = #{shopCarId} </if>		-->
		<if test="recruitId != null"> RECRUIT_ID = #{recruitId} </if>		--
		<if test="number != null"> ,NUMBER = #{number} </if>		
<!--		<if test="courseId != null"> ,COURSE_ID = #{courseId} </if>		-->
<!--		<if test="mode != null"> ,MODE = #{mode} </if>		-->
<!--		<if test="importMoney != null"> ,IMPORT_MONEY = #{importMoney} </if>		-->
<!--		<if test="courseName != null"> ,COURSE_NAME = #{courseName} </if>		-->
<!--		<if test="isDeleted != null"> ,IS_DELETED = #{isDeleted} </if>		-->
			<if test="updateAt != null"> ,UPDATE_AT = #{updateAt} </if>		
<!--		<if test="createAt != null"> ,CREATE_AT = #{createAt} </if>		-->
		where RECRUIT_ID = #{recruitId} and USER_ID = #{userId} and SCHOOL_ID = #{schoolId}
	</update>
</mapper>
这是我们一个类的基础代码
非常感谢你，我学会你这个xml的一些东西了，虽然，只是mybatis的皮毛 ... 很激动，会点了，谢谢你
xieyongcx 2014-01-17
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<?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="ShopCarMapper">
	<sql id="notDeletedSql"> is_deleted = 0 </sql> 
	<sql id="isDeletedSql"> is_deleted = 1 </sql> 
  <resultMap id="ShopCar" type="com.able.mycu.model.course.ShopCar">
		<result property="shopCarId" column="SHOP_CAR_ID" />
		<result property="recruitId" column="RECRUIT_ID" />
		<result property="number" column="NUMBER" />
		<result property="courseId" column="COURSE_ID" />
		<result property="mode" column="MODE" />
		<result property="importMoney" column="IMPORT_MONEY" />
		<result property="courseName" column="COURSE_NAME" />
		<result property="isDeleted" column="IS_DELETED" />
		<result property="updateAt" column="UPDATE_AT" />
		<result property="createAt" column="CREATE_AT" />
  </resultMap>

	<select id="getShopCarById" parameterType="int" resultMap="ShopCar">
		select * from TBL_SHOP_CAR where shop_car_id = #{shopCarId} and <include refid="notDeletedSql"/>

	</select>
	
	<select id="listShopCar" parameterType="com.able.mycu.search.course.ShopCarSearch" resultMap="ShopCar">
	    select * from TBL_SHOP_CAR where <include refid="notDeletedSql"/>
<!--		<if test="shopCarId != null"> and SHOP_CAR_ID = #{shopCarId} </if>	-->
<!--		<if test="recruitId != null"> and RECRUIT_ID = #{recruitId} </if>	-->
<!--		<if test="number != null"> and NUMBER = #{number} </if>	-->
<!--		<if test="courseId != null"> and COURSE_ID = #{courseId} </if>	-->
<!--		<if test="mode != null"> and MODE = #{mode} </if>	-->
<!--		<if test="importMoney != null"> and IMPORT_MONEY = #{importMoney} </if>	-->
<!--		<if test="courseName != null"> and COURSE_NAME like CONCAT('%','${COURSE_NAME}','%') </if>			-->
<!--		<if test="isDeleted != null"> and IS_DELETED like CONCAT('%','${IS_DELETED}','%') </if>			-->
<!--		<if test="updateAt != null"> and UPDATE_AT = #{updateAt} </if>	-->
<!--		<if test="createAt != null"> and CREATE_AT like CONCAT('%','${CREATE_AT}','%') </if>			-->
			<if test="schoolId != null"> and SCHOOL_ID=#{schoolId} </if>
			<if test="userId != null"> and USER_ID=#{userId} </if>			
	limit #{start},#{limit}
	</select>
	
	<select id="countShopCar" parameterType="com.able.mycu.search.course.ShopCarSearch" resultType="int">
		select count(1) from TBL_SHOP_CAR where <include refid="notDeletedSql"/>
<!--		<if test="shopCarId != null"> and SHOP_CAR_ID = #{shopCarId} </if>	-->
<!--		<if test="recruitId != null"> and RECRUIT_ID = #{recruitId} </if>	-->
<!--		<if test="number != null"> and NUMBER = #{number} </if>	-->
<!--		<if test="courseId != null"> and COURSE_ID = #{courseId} </if>	-->
<!--		<if test="mode != null"> and MODE = #{mode} </if>	-->
<!--		<if test="importMoney != null"> and IMPORT_MONEY = #{importMoney} </if>	-->
<!--		<if test="courseName != null"> and COURSE_NAME like CONCAT('%','${COURSE_NAME}','%') </if>			-->
<!--		<if test="isDeleted != null"> and IS_DELETED like CONCAT('%','${IS_DELETED}','%') </if>			-->
<!--		<if test="updateAt != null"> and UPDATE_AT = #{updateAt} </if>	-->
<!--		<if test="createAt != null"> and CREATE_AT like CONCAT('%','${CREATE_AT}','%') </if>			-->
	</select>
	
	<select id="listAllShopCar" parameterType="com.able.mycu.search.course.ShopCarSearch" resultMap="ShopCar">
	    select * from TBL_SHOP_CAR where <include refid="notDeletedSql"/>
<!--		<if test="shopCarId != null"> and SHOP_CAR_ID = #{shopCarId} </if>	-->
<!--		<if test="recruitId != null"> and RECRUIT_ID = #{recruitId} </if>	-->
<!--		<if test="number != null"> and NUMBER = #{number} </if>	-->
<!--		<if test="courseId != null"> and COURSE_ID = #{courseId} </if>	-->
<!--		<if test="mode != null"> and MODE = #{mode} </if>	-->
<!--		<if test="importMoney != null"> and IMPORT_MONEY = #{importMoney} </if>	-->
<!--		<if test="courseName != null"> and COURSE_NAME like CONCAT('%','${COURSE_NAME}','%') </if>			-->
<!--		<if test="isDeleted != null"> and IS_DELETED like CONCAT('%','${IS_DELETED}','%') </if>			-->
<!--		<if test="updateAt != null"> and UPDATE_AT = #{updateAt} </if>	-->
<!--		<if test="createAt != null"> and CREATE_AT like CONCAT('%','${CREATE_AT}','%') </if>			-->
			<if test="schoolId != null"> and SCHOOL_ID=#{schoolId} </if>
			<if test="userId != null"> and USER_ID=#{userId} </if>	
	</select>

	<insert id="saveShopCar" parameterType="com.able.mycu.model.course.ShopCar">
		insert into TBL_SHOP_CAR (
			<if test="recruitId != null"> RECRUIT_ID </if>
			<if test="number != null"> ,NUMBER </if>
			<if test="courseId != null"> ,COURSE_ID </if>
			<if test="mode != null"> ,MODE </if>
			<if test="importMoney != null"> ,IMPORT_MONEY </if>
			<if test="courseName != null"> ,COURSE_NAME </if>
			<if test="isDeleted != null"> ,IS_DELETED </if>
			<if test="updateAt != null"> ,UPDATE_AT </if>
			<if test="createAt != null"> ,CREATE_AT </if>
			<if test="userId != null"> ,USER_ID </if>
			<if test="schoolId != null"> ,SCHOOL_ID </if>
		)
		values (
		<if test="recruitId != null"> #{recruitId} </if>
		<if test="number != null"> ,#{number} </if>
		<if test="courseId != null"> ,#{courseId} </if>
		<if test="mode != null"> ,#{mode} </if>
		<if test="importMoney != null"> ,#{importMoney} </if>
		<if test="courseName != null"> ,#{courseName} </if>
		<if test="isDeleted != null"> ,#{isDeleted} </if>
		<if test="updateAt != null"> ,#{updateAt} </if>
		<if test="createAt != null"> ,#{createAt} </if>
		<if test="userId != null"> ,#{userId} </if>
		<if test="schoolId != null"> ,#{schoolId} </if>
		)
	<selectKey resultType="int" order="AFTER" keyProperty="shopCarId">
		SELECT LAST_INSERT_ID() AS shop_car_id
	</selectKey>
	</insert>

	<update id="removeShopCarByRecruitId" parameterType="hashmap" >
		delete from TBL_SHOP_CAR where RECRUIT_ID = #{recruitId} and USER_ID=#{userId} and schoolId =#{schoolId}
	</update>

	<update id="updateShopCarById" parameterType="com.able.mycu.model.course.ShopCar">
		update TBL_SHOP_CAR set 
<!--		<if test="shopCarId != null"> ,SHOP_CAR_ID = #{shopCarId} </if>		-->
		<if test="recruitId != null"> RECRUIT_ID = #{recruitId} </if>		--
		<if test="number != null"> ,NUMBER = #{number} </if>		
<!--		<if test="courseId != null"> ,COURSE_ID = #{courseId} </if>		-->
<!--		<if test="mode != null"> ,MODE = #{mode} </if>		-->
<!--		<if test="importMoney != null"> ,IMPORT_MONEY = #{importMoney} </if>		-->
<!--		<if test="courseName != null"> ,COURSE_NAME = #{courseName} </if>		-->
<!--		<if test="isDeleted != null"> ,IS_DELETED = #{isDeleted} </if>		-->
			<if test="updateAt != null"> ,UPDATE_AT = #{updateAt} </if>		
<!--		<if test="createAt != null"> ,CREATE_AT = #{createAt} </if>		-->
		where RECRUIT_ID = #{recruitId} and USER_ID = #{userId} and SCHOOL_ID = #{schoolId}
	</update>
</mapper>
这是我们一个类的基础代码
weidu23 2014-01-17
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引用 1 楼 xieyongcx 的回复:
你直接返回时需要映射的 截取一段映射代码给你 
  <resultMap id="ShopCar" type="com.able.mycu.model.course.ShopCar">
		<result property="shopCarId" column="SHOP_CAR_ID" />
		<result property="recruitId" column="RECRUIT_ID" />
		<result property="number" column="NUMBER" />
		<result property="courseId" column="COURSE_ID" />
		<result property="mode" column="MODE" />
		<result property="importMoney" column="IMPORT_MONEY" />
		<result property="courseName" column="COURSE_NAME" />
		<result property="isDeleted" column="IS_DELETED" />
		<result property="updateAt" column="UPDATE_AT" />
		<result property="createAt" column="CREATE_AT" />
  </resultMap>
可否截一段完整的给我看看，哪怕最简单只有一个参数也好！！！ 我手头上没多少资料抹黑学习。 想知道你那个一个最简单的完整的！(PS:网上百度都不全，所以学习半吊子水)
leox_2010 2014-01-17
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<resultMap id="BaseResultMap" type="cn.caculate.model.CalData" >
    <id column="cal_data_id" property="calDataId" jdbcType="INTEGER" />
    <result column="prjid" property="prjid" jdbcType="INTEGER" />
    <result column="data_file_id" property="dataFileId" jdbcType="INTEGER" />
    <result column="data_type" property="dataType" jdbcType="INTEGER" />
  </resultMap>
你先将你自己的实体对象映射成一个resultMap，然后在查询的select里面使用resultMap参数对其进行引用。如下： 
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from cal_data
    where cal_data_id = #{calDataId,jdbcType=INTEGER}
  </select>
xieyongcx 2014-01-17
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你直接返回时需要映射的 截取一段映射代码给你 
  <resultMap id="ShopCar" type="com.able.mycu.model.course.ShopCar">
		<result property="shopCarId" column="SHOP_CAR_ID" />
		<result property="recruitId" column="RECRUIT_ID" />
		<result property="number" column="NUMBER" />
		<result property="courseId" column="COURSE_ID" />
		<result property="mode" column="MODE" />
		<result property="importMoney" column="IMPORT_MONEY" />
		<result property="courseName" column="COURSE_NAME" />
		<result property="isDeleted" column="IS_DELETED" />
		<result property="updateAt" column="UPDATE_AT" />
		<result property="createAt" column="CREATE_AT" />
  </resultMap>
weidu23 2014-01-17
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引用 8 楼 chenxyz707 的回复:
你可以使用resultType或者resultMap。resultType可以写类的路径，resultMap就是上面说的xml中定义的<resultMap></resultMap>。
我上面的题目就是用resultType=“” 但是返回的就是Null,你可以看看我的提问，如下：zxw.model.UserInf 

<mapper namespace="zxw.dao.UserInfMapper" >
      <!-- public UserInf selectPublicName(String userName); -->
      <select id="obtainedPublicName" resultType="zxw.model.UserInf" parameterType="java.lang.String">
      select * from userInf where user_name = #{userName,jdbcType=VARCHAR}
  </select>
</mapper>
chenxyz707 2014-01-17
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你可以使用resultType或者resultMap。resultType可以写类的路径，resultMap就是上面说的xml中定义的<resultMap></resultMap>。
Mybatis动态SQL & ResultType = hashMap
mybatis update set 多个字段 <update id="updateCustomer" parameterType="com.entrym.domain.Customer"> UPDATE customer set <if test="name!=null">name=#{name,jdbcType=VARCHAR},</if> &...
Mybatis中resultType为hashmap的情况
现在有一张user表  id ,name,age 我们进行一个简单的查询： &lt;select id="test" resultType="Uer"&gt;  select id ,name,age from user &lt;/select&gt; 查询完后，...
Mybatis，resultType=“HashMap“，HashMap存储查询结果
表示stuNo这一列作为hashmap的key值，value值为Studeng类;
mybatis使用resultType=hashmap时发现值为null的参数没有返回导致空指针异常
解决方法：配置mybatis配置中的callSettersOnNulls参数为ture; 官网是这样介绍这个参数的： 指定当结果集中值为 null 的时候是否调用映射对象的 setter（map 对象时为 put）方法，这在依赖于 Map.keySet() 或 null ...
MyBatis resultMap type="HashMap"
MyBatis <resultMap type="HashMap
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