1.导入Jar包
mybatis-3.4.4.jar
mysql-connector-java-8.0.11.jar
2.编写Mybatis的配置文件
<?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> <!-- 这个是配置数据库的信息 --> <environments default="mysql"> <environment id="mysql"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql:///dt48_mybatis?serverTimezone=GMT"/> <property name="username" value="root"/> <property name="password" value="zhangpn"/> </dataSource> </environment> </environments> <!-- 关联局部配置文件 --> <mappers> <mapper resource="cn/java/dao/impl/UserDaoImpl.xml"/> </mappers> </configuration>
3.创建一个pojo类
1 /** 2 * Project Name:dt48_mybatis1 3 * File Name:User.java 4 * Package Name:cn.java.entity 5 * Date:下午4:03:45 6 * Copyright (c) 2017, bluemobi All Rights Reserved. 7 * 8 */ 9 10 package cn.java.entity; 11 12 public class User { 13 private Long id;// 主键 14 15 private String username;// 用户名 16 17 private String password;// 密码 18 19 public Long getId() { 20 return id; 21 } 22 23 public void setId(Long id) { 24 this.id = id; 25 } 26 27 public String getUsername() { 28 return username; 29 } 30 31 public void setUsername(String username) { 32 this.username = username; 33 } 34 35 public String getPassword() { 36 return password; 37 } 38 39 public void setPassword(String password) { 40 this.password = password; 41 } 42 43 @Override 44 public String toString() { 45 return "User [id=" + id + ", username=" + username + ", password=" + password + "]"; 46 } 47 }
4.编写一个局部配置文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE mapper 3 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 5 6 <mapper namespace="cn.java.dao.impl.UserDaoImpl"> 7 8 <select id="getAllUser" resultType="cn.java.entity.User"> 9 SELECT * FROM users 10 </select> 11 12 <!-- 13 select语句返回List<Map<String,Object> 14 --> 15 <select id="getAllUser22" resultType="Map"> 16 SELECT * FROM users 17 </select> 18 </mapper>
5.调用执行测试结果
/** * Project Name:dt48_mybatis1 * File Name:UserDaoImpl.java * Package Name:cn.java.dao.impl * Date:下午3:39:43 * Copyright (c) 2017, bluemobi All Rights Reserved. * */ package cn.java.dao.impl; import java.io.IOException; import java.io.InputStream; import java.util.List; import java.util.Map; 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 cn.java.entity.User; import sun.applet.Main; /** * Description: <br/> * Date: 下午3:39:43 <br/> * * @author dingP * @version * @see */ public class UserDaoImpl { public static void main(String[] args) throws IOException { SqlSessionFactoryBuilder sfb = new SqlSessionFactoryBuilder(); // 将mybatis.xml文件转化成流 InputStream ins = Resources.getResourceAsStream("mybatis.xml"); SqlSessionFactory ssf = sfb.build(ins); SqlSession session = ssf.openSession(); // 2、调用局部配置文件中的sql语句 List<User> userList = session.selectList("cn.java.dao.impl.UserDaoImpl.getAllUser"); for (User user : userList) { System.out.println(user); } } public void getAllUser() throws IOException { // 1、启动mybatis框架 // SqlSession---->SqlSessionFactory---->SqlSessionFactoryBuilder SqlSessionFactoryBuilder sfb = new SqlSessionFactoryBuilder(); // 将mybatis.xml文件转化成流 InputStream ins = Resources.getResourceAsStream("mybatis.xml"); SqlSessionFactory ssf = sfb.build(ins); SqlSession session = ssf.openSession(); // 2、调用局部配置文件中的sql语句 List<User> userList = session.selectList("cn.java.dao.impl.UserDaoImpl.getAllUser"); for (User user : userList) { System.out.println(user); } } public void getAllUser22() throws IOException { // 1、启动mybatis框架 // SqlSession---->SqlSessionFactory---->SqlSessionFactoryBuilder SqlSessionFactoryBuilder sfb = new SqlSessionFactoryBuilder(); // 将mybatis.xml文件转化成流 InputStream ins = Resources.getResourceAsStream("mybatis.xml"); SqlSessionFactory ssf = sfb.build(ins); SqlSession session = ssf.openSession(); // 2、调用局部配置文件中的sql语句 List<Map<String, Object>> userList = session.selectList("cn.java.dao.impl.UserDaoImpl.getAllUser22"); for (Map<String, Object> map : userList) { System.out.println(map); } } }