MyBatis-plus SQLFeatureNotSupportedException 的解决办法

如图，SQLITE 的这个驱动似乎不支持使用 getBLOB，但 SQLITE 确实支持存储 BLOB 数据，如果用 Mybatis 也会遇到同样的问题, 毕竟 MP 是基于 MyBatis 的

解决办法也很简单，加上这个参数就行

或者也可以给某个字段加上 typeHandler 的参数，然后写一个 TypeHandler，这样就能指定 注入这个字段时使用的 TypeHandler

第二个方法只使用 Mybatis 也能用，只是需要在 xml 里配置 typeHandler

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2022-05-08 更新 Mybatis xml 配置方式

最近又用到这个了，这次没有 SpringBoot 的加持, 麻烦了些许，贴上代码
项目结构

mybatis-config.xml

<?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>

    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

    <typeAliases>
        <typeAlias alias="Question" type="com.mrx.jkbd.entity.Question"/>
    </typeAliases>

    <typeHandlers>
        <typeHandler javaType="byte[]" handler="com.mrx.mybatis.config.ByteArrayTypeHandler"/>
    </typeHandlers>

    <environments default="development">

        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="com.mrx.mybatis.config.XDruidDataSourceFactory">
                <property name="name" value="SQLITE"/>
                <property name="url" value="jdbc:sqlite::resource:question.db"/>
                <property name="driverClassName" value="org.sqlite.JDBC"/>
                <property name="initialSize" value="5"/>
                <property name="minIdle" value="5"/>
                <property name="maxActive" value="10"/>
                <property name="maxWait" value="10000"/>
                <property name="validationQuery" value="SELECT 1"/>
            </dataSource>
        </environment>

    </environments>

    <mappers>
        <mapper resource="mapper/QuestionMapper.xml"/>
    </mappers>

</configuration>

QuestionMapper.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.mrx.mybatis.mapper.QuestionMapper">

    <resultMap id="questionMap" type="Question">
        <result column="question" property="question" javaType="byte[]"/>
        <result column="explain" property="explain" javaType="byte[]"/>
        <result column="keywords" property="keywords" javaType="byte[]"/>
        <result column="concise_explain" property="conciseExplain" javaType="byte[]"/>
        <result column="assured_keywords" property="assuredKeywords" javaType="byte[]"/>
        <result column="illiteracy_explain" property="illiteracyExplain" javaType="byte[]"/>
        <result column="illiteracy_keywords" property="illiteracyKeywords" javaType="byte[]"/>
        <result column="knack_keyword" property="knackKeyword" javaType="byte[]"/>
        <result column="knack_img_url" property="knackImgUrl" javaType="byte[]"/>
        <result column="knack_detail" property="knackDetail" javaType="byte[]"/>
        <result column="knack_voice_txt" property="knackVoiceTxt" javaType="byte[]"/>
    </resultMap>

    <select id="getQuestionById" resultType="Question" parameterType="long" resultMap="questionMap">
        SELECT *
        FROM t_question
        WHERE question_id = #{qid}
    </select>

</mapper>

ByteArrayTypeHandler

package com.mrx.mybatis.config

import org.apache.ibatis.type.JdbcType
import org.apache.ibatis.type.TypeHandler
import org.slf4j.LoggerFactory
import java.sql.CallableStatement
import java.sql.PreparedStatement
import java.sql.ResultSet

/**
 * @author Mr.X
 * @since 2022-05-08-0008
 **/
@Suppress("unused")
class ByteArrayTypeHandler : TypeHandler<ByteArray> {

    private val logger = LoggerFactory.getLogger(this::class.java)

    override fun setParameter(ps: PreparedStatement, i: Int, parameter: ByteArray, jdbcType: JdbcType) {
        ps.setBytes(i, parameter)
    }

    override fun getResult(rs: ResultSet, columnName: String): ByteArray? {
        return rs.getBytes(columnName)
    }

    override fun getResult(rs: ResultSet, columnIndex: Int): ByteArray? {
        return rs.getBytes(columnIndex)
    }

    override fun getResult(cs: CallableStatement, columnIndex: Int): ByteArray? {
        return cs.getBytes(columnIndex)
    }

}

MyBatisUtil

package com.mrx.mybatis.config

import org.apache.ibatis.session.SqlSessionFactory
import org.apache.ibatis.session.SqlSessionFactoryBuilder
import java.io.InputStream


/**
 * 配置 Mybatis
 */
object MybatisUtil {

    private val ins: InputStream = this::class.java.getResourceAsStream("/mybatis-config.xml")!!

    //定义默认 environment
    private val env: SqlSessionFactory = SqlSessionFactoryBuilder().build(ins)

    fun <T> getMapper(mapperClazz: Class<T>): T {

        return env.configuration.getMapper(mapperClazz, env.openSession())
    }

}