Mybatis使用流程
1. 引入mybatis.jar和mysql-connector.jar包
先创建项目,然后引入jar包,方便接下来的操作
2. XML 配置文件书写
XML位置:在src目录下,与其他包平齐
XML配置文件作用:包含MyBatis 系统的核心设置,包括获取数据库连接实例的数据源(DataSource)以及决定事务作用域和控制方式的事务管理器(TransactionManager)
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 配置MyBatis运行环境-->
<environments default="development">
<environment id="development">
<!-- 配置JDBC事务管理-->
<transactionManager type="JDBC"/>
<!-- 用POOLED配置JDBC数据源连接池-->
<dataSource type="POOLED">
<!-- 取到JDBC的连接-->
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<!-- 连接数据库,geek是我的数据库名称-->
<property name="url" value="jdbc:mysql://localhost:3306/geek"/>
<!-- 连接数据库,root是我的数据库服务账号-->
<property name="username" value="root"/>
<property name="password" value="数据库密码"/>
</dataSource>
</environment>
</environments>
<!-- 配置mapper映射文件,用'/'的目的是因为最有一个文件有xml后缀,方便区分文件和目录-->
<mappers>
<mapper resource="com/geek/mapper/AccountMapper.xml"/>
</mappers>
</configuration>
3. 创建数据库表
information
4. 创建数据类
Account
public class Account {
private int id;
private String username;
private String password;
private int age;
public Account() {
}
public Account(int id, String username, String password, int age) {
this.id = id;
this.username = username;
this.password = password;
this.age = age;
}
public int getId() {
return id;
}
public void setId(int 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 int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Account [id=" + id + ", username=" + username + ", password=" + password + ", age=" + age + "]";
}
}
5. 创建映射关系
AccountMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace就是自己这个xml-->
<mapper namespace="com.geek.mapper.AccountMapper">
<!-- insert就是对应的插入操作,select对应选择,以此类推-->
<!-- id就是自动创建的方法名,自己写就行,parameterType是方法的参数类型,还有returnType等-->
<insert id="save" parameterType="com.geek.mybatis.Account">
<!-- 这里写SQL语句,相当于方法体,values里面的用#{属性名}的形式-->
insert into information(username,password,age) values(#{username},#{password},#{age})
</insert>
</mapper>
6. 写测试函数
import java.io.IOException;
import java.io.InputStream;
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 com.geek.mybatis.Account;
public class Test {
public static void main(String[] args) {
// 加载MyBatis配置文件
try {
// resource是前面的XML配置文件路径
String resource = "config.xml";
//固定写法得到sqlSession
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession sqlSession = sqlSessionFactory.openSession();
//获取mapper文件中写好的方法,这里是save(那个xml文件对应的某个id)
String statement = "com.geek.mapper.AccountMapper.save";
Account account = new Account(2,"张三", "123456",20);
//调用方法
sqlSession.insert(statement, account);
//提交到数据库
sqlSession.commit();
} catch (IOException e) {
}
}
}