🍁环境
- JDK1.8
- Mysql5.7
- maven 3.6.3
- IDEA
🍁第一个MyBatis程序
步骤：
搭建环境–>导入Mybatis–>编写代码–>测试。
🔥搭建环境
- 搭建数据库
- 新建项目
- 新建一个普通maven项目
- 导入maven依赖
🔥搭建数据库
1.创建一个数据库名为mybatis的tb_user表
2.向表中添加数据
🔥导入maven依赖
pom:
- maven依赖代码置于 pom.xml 文件中：
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.6</version>
</dependency>- 导入MySQL驱动的依赖
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>-单元测试依赖
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>🔥编写mybatis-config.xml的核心配置文件
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 core file-->
<configuration>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<!--加载sql映射文件-->
<mappers>
<mapper resource="com.jkj.UserMapper.xml"/>
</mappers>
</configuration>
🔥 编写Mapper.xml的配置文件
userMapper.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="test">
<select id="selectAll" resultType="com.jkj.pojo.User">
select * from tb_user;
</select>
</mapper>🔥 编写User实体类代码：
package com.jkj.pojo;
public class User {
private Integer id;
private String username;
private String password;
private String gender;
private String addr;
public User() {
}
public User(Integer id, String username, String password, String gender, String addr) {
this.id = id;
this.username = username;
this.password = password;
this.gender = gender;
this.addr = addr;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getAddr() {
return addr;
}
public void setAddr(String addr) {
this.addr = addr;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
", gender='" + gender + '\'' +
", addr='" + addr + '\'' +
'}';
}
}
🔥编写mybatisTest测试类
MyBatisUtils：
import com.jkj.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 java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class MybatisTest {
public static void main(String[] args) throws IOException {
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.执行sql
List<User> users = sqlSession.selectList("test.selectAll");
System.out.println(users);
//4.释放资源
sqlSession.close();
}
}
🔥运行截图：
