Mybatis入门：（1）环境搭建及第一个实例

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一、环境：Eclipse、Mysql、Mysql驱动包、Mybatis3.jar

二、项目结构（这里创建的是java项目，不是web的）

三、数据库脚本

CREATE TABLE `user` (  `id` int(11) NOT NULL,  `name` varchar(45) NOT NULL,  `dept` varchar(200) NOT NULL,  `website` varchar(200) DEFAULT NULL,  `phone` varchar(16) NOT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户表';SELECT * FROM db_lin.user;

四、实例代码

1、user.java

package com.linbilin.mybatis.models;public class User {private int id;private String name;private String dept;private String phone;private String website;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 String getDept() {return dept;}public void setDept(String dept) {this.dept = dept;}public String getPhone() {return phone;}public void setPhone(String phone) {this.phone = phone;}public String getWebsite() {return website;}public void setWebsite(String website) {this.website = website;}@Overridepublic String toString() {return "User [id=" + id + ", name=" + name + ", dept=" + dept+ ", phone=" + phone + ", website=" + website + "]";}}

2、User.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"><!-- 此时这个namespace的值可以随便写，你这边可以把namespace理解为一个类，select的id理解为namespace这个类的一个方法名。但如果是按照接口来编程的话，namespace就得写接口的全路径了 --><mapper namespace="com.linbilin.mybatis.models.UserMapper"><select id="getUserByID" parameterType="int" resultType="User">select * from `user` where id = #{id}    </select></mapper>

3、MybatisUtils.java

package com.linbilin.mybatis.utils;import java.io.Reader;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class MybatisUtils {private static SqlSessionFactory sqlSessionFactory;private static Reader reader;static {try {reader = Resources.getResourceAsReader("config/Configure.xml");sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);} catch (Exception e) {e.printStackTrace();}}public static SqlSessionFactory getSession() {return sqlSessionFactory;}}

4、Configure.xml，配置数据源

<?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><typeAliases><typeAlias alias="User" type="com.linbilin.mybatis.models.User" /></typeAliases><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://127.0.0.1:3306/db_lin" />    <property name="username" value="root" />    <property name="password" value="ls" />            </dataSource></environment></environments><mappers>      <mapper resource="com/linbilin/mybatis/models/User.xml" /></mappers></configuration>

5、MyTest.java

package com.linbilin.mybatis.test;import org.apache.ibatis.session.SqlSession;import com.linbilin.mybatis.models.User;import com.linbilin.mybatis.utils.MybatisUtils;public class MyTest {public static void main(String[] args) {SqlSession session = MybatisUtils.getSession().openSession();try {User user = (User) session.selectOne("com.linbilin.mybatis.models.UserMapper.getUserByID", 1);if (user != null) {String userInfo = user.toString();System.out.println(userInfo);}} catch (Exception e) {e.printStackTrace();}finally{session.close();// 关闭session，释放资源}}}

五、运行结果

六、附件

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