mybatis框架入门教程(mysql数据库)(一)
1.先去mybatis官网把mybatis的jar下载下来,我用的3.1.1版本。mybatis的jar和连接mysql数据库的jar都放进创建的java工程里面。
2.创建mybatis数据库与user表
3.创建如图所示的包及xml文件。
4.配置文件conf.xml(前两行的文档类型必须写不然会报错)
<?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> <!-- development : 开发模式 work : 工作模式 --> <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" /> <property name="username" value="root" /> <property name="password" value="" /> </dataSource> </environment> </environments> <mappers> <!-- 写mapper所在的包的路径 --> <mapper resource="com/kpzc/test1/userMapper.xml"/> </mappers> </configuration>
5.创建user的bean
package com.kpzc.bean; public class User { private int id; private String name; private int age; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public User() { super(); } public User(int id, String name, int age) { super(); this.id = id; this.name = name; this.age = age; } @Override public String toString() { return "User [id=" + id + ", name=" + name + ", age=" + age + "]"; } }
6.写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"> <!-- 一般写包的路径(不带.xml) --> <mapper namespace="com.kpzc.test1.userMapper"> <!-- 根据id查询得到一个user对象 parameterType id的参数类型 resultType 写bean对象 --> <select id="getUser" parameterType="int" resultType="com.kpzc.bean.User"> select * from users where id=#{id} </select> </mapper>
7.最后写一个测试方法
package com.kpzc.test1; import java.io.IOException; import java.io.InputStream; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import com.kpzc.bean.User; /* * @author kpzc */ public class Test { public static void main(String[] args) throws IOException { //加载mybatis的配置文件,也加载关联的映射文件 String resource = "conf.xml"; InputStream is = Test.class.getClassLoader().getResourceAsStream(resource); //构建SqlSession工厂 SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is); //创建能执行映射文件中sql的SqlSession SqlSession session = factory.openSession(); //映射sql标识字符串 String statement = "com.kpzc.test1.userMapper.getUser"; //执行查询返回一个指定的user User user = session.selectOne(statement,1); System.out.println(user); } }
8.运行结果
有什么不正之处欢迎大家之处,鄙人不胜感激。