MyBatis的基本使用步骤

MyBatis的基本使用步骤（以超市管理系统为例）

1.下载需要的jar包

2.. 部署jar文件
将jar文件部署到项目的lib目录下
如下图：

3.创建MyBatis核心配置文件–mybatis-config.xml
mybatis-config.xml配置如下：

<?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">
<!-- 通过这个配置文件完成mybatis与数据库的连接 -->
<configuration>
    <!-- 引入数据源配置 database.properties 文件 -->
    <properties resource="database.properties"></properties>

    <!--配置mybatis 运行中的一些行为 -->
    <settings>
        <!-- 设置Mybatis的log实现为LOG4J -->
        <setting name="logImpl" value="LOG4J"/>
    </settings>

    <typeAliases>
        <!-- 
        <typeAlias alias="User" type="com.zy.entity.User"/>
         -->
        <package name="cn.zy.entity"/>
    </typeAliases>

    <!-- 配置mybatis运行环境 -->
    <environments default="dev">
        <environment id="dev">
            <!-- 采用jdbc事务管理 -->
            <transactionManager type="JDBC"></transactionManager>
            <!-- 采用Mybatis自带的数据源 POOLED -->
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${user}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    <!-- 将mapper文件加入到配置文件中 -->
    <mappers>
        <mapper resource="cn/zy/dao/UserMapper.xml"/>
    </mappers>
</configuration>

4.创建持久化类和SQL映射文件

 (1)创建实体类(User.java)

package cn.zy.entity;

import java.util.Date;

public class User {
    private Integer id; //id 
    private String userCode; //用户编码
    private String userName; //用户名称
    private String userPassword; //用户密码
    private Integer gender;  //性别
    private Date birthday;  //出生日期
    private String phone;   //电话
    private String address; //地址
    private Integer userRole;    //用户角色
    private String userRoleName; //角色名称
    private Integer createdBy;   //创建者
    private Date creationDate; //创建时间
    private Integer modifyBy;     //更新者
    private Date modifyDate;   //更新时间
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getUserCode() {
        return userCode;
    }
    public void setUserCode(String userCode) {
        this.userCode = userCode;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getUserPassword() {
        return userPassword;
    }
    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }
    public Integer getGender() {
        return gender;
    }
    public void setGender(Integer gender) {
        this.gender = gender;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public Integer getUserRole() {
        return userRole;
    }
    public void setUserRole(Integer userRole) {
        this.userRole = userRole;
    }
    public String getUserRoleName() {
        return userRoleName;
    }
    public void setUserRoleName(String userRoleName) {
        this.userRoleName = userRoleName;
    }
    public Integer getCreatedBy() {
        return createdBy;
    }
    public void setCreatedBy(Integer createdBy) {
        this.createdBy = createdBy;
    }
    public Date getCreationDate() {
        return creationDate;
    }
    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }
    public Integer getModifyBy() {
        return modifyBy;
    }
    public void setModifyBy(Integer modifyBy) {
        this.modifyBy = modifyBy;
    }
    public Date getModifyDate() {
        return modifyDate;
    }
    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }
}

(2)创建UserMapper.xml映射文件

<?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="cn.zy.dao.UserMapper">
    <!-- 查询记录数 -->
    <select id="count" resultType="int">
        select count(1) from smbms_user
    </select>

    <!-- 查询所有用户 -->
    <select id="list" resultType="User">
        select * from smbms_user
    </select>
</mapper>

5.创建测试类（UserTest.java）

package cn.zy.test;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

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 org.apache.log4j.Logger;
import org.junit.Test;

import cn.zy.dao.UserMapper;
import cn.zy.entity.User;
import cn.zy.util.MyBatisUtil;

public class UserTest {

    Logger logger = Logger.getLogger(UserTest.class);

    @Test
    public void testList() {

        try {
            //读取Mybatis核心配置文件,放至输入流中(内存)
            String resource = "mybatis-config.xml";
            InputStream is = Resources.getResourceAsStream(resource);

            //创建SessionFactory对象，读取配置信息
            SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);

            //创建一个session
            SqlSession session = factory.openSession();

            //Mybatis通过mapper文件的namespace和子元素的id来找到相应的SQL，从而执行查询操作
            int count = session.selectOne("cn.zy.dao.UserMapper.count");
            logger.debug(count);
            List<User> list = session.selectList("cn.zy.dao.UserMapper.list");
            for (User user : list) {
                logger.debug(user.getUserName());
            }
            //关闭session
            session.close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

6.提示：最好弄个工具类，使用起来更方便。这里只写了一种方式，还有另一种方式这里就不介绍了。