准备工作：1.创建一个maven工程，然后将pojo类导入到项目中去。
2.导入依赖到pom.xml文件中
3.在resources中创建log4j.properites和mybatis-config.xml
4.创建UserMapper接口和UserMapper.xml文件
5.创建测试类MyBatisTest
1.创建Maven工程，还没有配置Maven的和还不会的去看这里啦：maven的下载安装与配置环境变量！！！（全网最详细）-CSDN博客
2.导入依赖到pom.xml文件中
<dependencies><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.4.5</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.17</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency></dependencies><build><!-- 如果不添加此节点src/main/java目录下的所有配置文件都会被漏掉。 --><resources><resource><directory>src/main/java</directory><includes><include>**/*.xml</include></includes></resource><resource><directory>src/main/resources</directory></resource></resources></build>3.在resources中创建log4j.properites和mybatis-config.xml
log4j.properites:
# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%nmybatis-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><!--使用dev环境--><environments default="dev"><!--dev环境--><environment id="dev"><transactionManager type="JDBC"></transactionManager><!--使用连接池中的数据源--><dataSource type="POOLED"><property name="driver" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql://127.0.0.1:3305/mybatis?characterEncoding=UTF-8"/><property name="username" value="root"/><property name="password" value=""/></dataSource></environment></environments><!-- 扫描映射文件 --><mappers><mapper resource="com/by/mapper/UserMapper.xml"/></mappers>
</configuration>4.创建UserMapper接口和UserMapper.xml文件
UserMapper.java:
package com.by.mapper;import com.by.pojo.User;
import org.apache.ibatis.annotations.Param;import java.util.Map;/*** <p>Project: mybatis - UserMapper</p>* <p>Powered by scl On 2023-12-19 15:24:18</p>* <p>描述：<p>** @author 孙臣龙 [1846080280@qq.com]* @version 1.0* @since 17*/
public interface UserMapper {User getUserById(Integer id );User getUser(Integer id , String username);User getUser1(@Param("id") Integer id , @Param("username") String username);User getUser2(User user);User getUser3(Map<String ,Object> map);
}
UserMapper.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.by.mapper.UserMapper"><select id="getUserById" resultType="com.by.pojo.User">select * from user where id=#{id}</select><select id="getUser" resultType="com.by.pojo.User"><!--select * from user where id=#{arg0} and username=#{arg1};-->select * from user where id=#{param1} and username=#{param2};</select><select id="getUser1" resultType="com.by.pojo.User">select * from user where id=#{id} and username=#{username}</select><select id="getUser2" parameterType="com.by.pojo.User" resultType="com.by.pojo.User">select * from user where id=#{id} and username=#{username}</select><select id="getUser3" parameterType="java.util.Map" resultType="com.by.pojo.User">select * from user where id=#{id} and username=#{username}</select>
</mapper>
5.创建测试类MyBatisTest
/** Copyright (c) 2020, 2023, All rights reserved.**/
package com.by;import com.by.mapper.UserMapper;
import com.by.pojo.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.After;
import org.junit.Before;
import org.junit.Test;import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;/*** <p>Project: mybatis - MyBatisTest</p>* <p>Powered by scl On 2023-12-18 11:44:53</p>* <p>描述：<p>** @author 孙臣龙 [1846080280@qq.com]* @version 1.0* @since 17*/
public class MyBatisTest {private InputStream inputStream;private SqlSession sqlSession;@Beforepublic void init() throws IOException {// 加载配置文件String resource = "mybatis-config.xml";inputStream = Resources.getResourceAsStream(resource);// 创建sqlSessionFActorySqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream);// 获得数据的绘画实例sqlSession = sessionFactory.openSession();}/*** 传递单个参数* @throws IOException*/@Testpublic void testGetById() throws IOException {UserMapper userMapper = sqlSession.getMapper(UserMapper.class);User user = userMapper.getUserById(43);System.out.println(user);}/*** 传递多个参数* @throws IOException*/@Testpublic void testGetUser() throws IOException {UserMapper userMapper = sqlSession.getMapper(UserMapper.class);User user = userMapper.getUser(43,"俞莲舟");System.out.println(user);}/*** 注解传递多个参数* @throws IOException*/@Testpublic void testGetUser1() throws IOException {UserMapper userMapper = sqlSession.getMapper(UserMapper.class);User user = userMapper.getUser(43,"俞莲舟");System.out.println(user);}/*** 对象传递多个参数* @throws IOException*/@Testpublic void testGetUser2() throws IOException {UserMapper userMapper = sqlSession.getMapper(UserMapper.class);User user1 = new User();user1.setId(43);user1.setUsername("俞莲舟");User user = userMapper.getUser2(user1);System.out.println(user);}/*** map传递多个参数* @throws IOException*/@Testpublic void testGetUser3() throws IOException {UserMapper userMapper = sqlSession.getMapper(UserMapper.class);Map<String ,Object> m = new HashMap<>();m.put("id",43);m.put("username","俞莲舟");User user = userMapper.getUser3(m);System.out.println(user);}@Afterpublic void close() throws IOException {inputStream.close();sqlSession.close();}}
