1.配置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">
<!-- 核心配置文件 -->
<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC"/>
<property name="username" value="root"/>
<property name="password" value="123"/>
</dataSource>
</environment>
</environments>
<!-- 注意绑定 -->
<mappers>
<mapper resource="com\sun\dao\UserMapper.xml"></mapper>
</mappers>
</configuration>
2.maven 项目注意资源过滤
<!-- 静态资源导出问题 -->
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
3.进行Mapper.xml的编写
namespace 要与dao层的一致,注意全限定名
<?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.sun.dao.UserDao">
<select id="getUserList" resultType="com.sun.pojo.User">
select * from user
</select>
</mapper>
4.UserDao.java
package com.sun.dao;
import com.sun.pojo.User;
import java.util.List;
public interface UserDao {
List<User> getUserList();
}
5.mybatisUtils.java
package com.sun.utils;
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 java.io.IOException;
import java.io.InputStream;
//sqlSessionFactory
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
try {
//获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = null;
inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}
}
6.maven项目中导入依赖
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.18</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.3</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
7.Test junit测试
package com.sun.dao;
import com.sun.pojo.User;
import com.sun.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
public class UserDaoTest {
@Test
public void test(){
SqlSession sqlSession = MybatisUtils.getSqlSession();
UserDao mapper = sqlSession.getMapper(UserDao.class);
for (User user : mapper.getUserList()) {
System.out.println(user);
}
sqlSession.close();
}
}
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