Mybatis --04.mybatis中parameterType参数类型

本文主要是介绍Mybatis --04.mybatis中parameterType参数类型，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

parameterType有三种类型的输入参数

1、基本数据类型

2、hashmap

3、pojo包装类

前面已使用过了基本数据类型和pojo类型的参数。下面使用hashmap类型

UserDaoMapper.xml中添加login

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--映射文件的作用：用来存放sql语句namespace:命名空间
-->
<mapper namespace="UserDaoMapper"><!--登录--><select id="login" resultType="User" parameterType="hashmap" >select * from tb_user where user_name = #{userName} and password = #{password}</select>
</mapper>

UserDao接口中添加login方法：

package com.sswblog.dao;import com.sswblog.domain.User;import java.util.List;/*** @ Author     ：ShaoWei Sun.* @ Date       ：Created in 0:06 2018/11/5*//*** 登录* @param userName* @param password* @return*/public User login(String userName, String password);
}

UserDaoImpl中实现login方法：

package com.sswblog.dao.Impl;import com.sswblog.dao.UserDao;
import com.sswblog.domain.User;
import org.apache.ibatis.session.SqlSession;import java.util.HashMap;
import java.util.List;
import java.util.Map;/*** @ Author     ：ShaoWei Sun.* @ Date       ：Created in 0:06 2018/11/5*/
public class UserDaoImpl implements UserDao {//dao层增删除改查需要SqlSessionprivate SqlSession sqlSession = null;//构造方法public UserDaoImpl(SqlSession sqlSession) {this.sqlSession = sqlSession;}@Overridepublic User login(String userName, String password) {Map<String,Object> map = new HashMap<>();map.put("userName",userName);map.put("password",password);User user = this.sqlSession.selectOne("UserDaoMapper.login", map);return user;}
}

UserDaoTest中添加testLogin方法

package com.sswblog.test;import com.sswblog.dao.Impl.UserDaoImpl;
import com.sswblog.dao.UserDao;
import com.sswblog.domain.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;import java.io.InputStream;
import java.util.Date;
import java.util.List;/*** @ Author     ：ShaoWei Sun.* @ Date       ：Created in 15:05 2018/11/5*/
public class UserDaoImplTest {private UserDao userDao = null;@Beforepublic void setUp() throws Exception {InputStream in = Resources.getResourceAsStream("mybatis-config.xml");SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);SqlSession sqlSession = sqlSessionFactory.openSession();userDao = new UserDaoImpl(sqlSession);}@Testpublic void login(){User user = userDao.login("小王", "111111");if (user == null){System.out.println("没有登录");}else {System.out.println("登录成功");}System.out.println(user);}
}