mybatis出现无效的列类型

package com.webapp.hanqi.test;

import java.util.Date;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.webapp.hanqi.dao.AppUserDao;
import com.webapp.hanqi.model.AppUser;

class AppWebTest {

    ClassPathXmlApplicationContext c;
    AppUserDao appUserDao;

    @Test
    void test() {
        AppUser user = new AppUser();
        user.setUname("admin333");
        user.setPword("123");
        user.setCtime(new Date());
        user.setRname("测试用户");
        // user.setEmail("25673578@qq.com");
        user.setCdkey("abc");
        int u = appUserDao.insert(user);
        System.out.println(u);
    }

    @BeforeEach
    void setUp() throws Exception {
        c = new ClassPathXmlApplicationContext("conf/spring-all.xml");
        appUserDao = c.getBean(AppUserDao.class);
    }

    @AfterEach
    void tearDown() throws Exception {
        c.close();
    }

}

添加一条数据时, email列被报出无效的列类型的异常, 原因是mybatis在插入空值的时候需要指定jdbcType, 否则将无法进行转换