Mybatis环境搭建

1. 新建一个maven 普通java工程

image.png

2. 导入依赖

   <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <!--Mybatis-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.5</version>
    </dependency>

    <!--Mysql-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <scope>runtime</scope>
      <version>5.1.46</version>
    </dependency>

    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>

3. 日志配置（log4j.properties）

### 设置###
log4j.rootLogger = debug,stdout,D,E

### 输出信息到控制抬 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern =  %-d{yyyy-MM-dd HH:mm:ss}  [%t] - [%p]  %m%n

### 输出DEBUG 级别以上的日志到=E://logs/error.log ###
#log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
#log4j.appender.D.File = E://logs/log.log
#log4j.appender.D.Append = true
#log4j.appender.D.Threshold = DEBUG
#log4j.appender.D.layout = org.apache.log4j.PatternLayout
#log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

### 输出ERROR 级别以上的日志到=E://logs/error.log ###
#log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
#log4j.appender.E.File =E://logs/error.log
#log4j.appender.E.Append = true
#log4j.appender.E.Threshold = ERROR
#log4j.appender.E.layout = org.apache.log4j.PatternLayout
#log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

4. 创建对应数据库表的实体类和接口

目录结构
User.java

package com.test.pojo;

import java.io.Serializable;
import java.text.SimpleDateFormat;
import java.util.Date;

public class User implements Serializable {
    private Integer id;
    private String userName;
    private Date birthday;
    private String sex;
    private String address;


    public Integer getId() {
        return id;
    }
    //More_get_And_Set ...
}

UserDao.java

package com.test.dao;

import com.test.pojo.User;

import java.util.List;

public interface UserDao {

    List<User> findAll();

    int save(User u);
}

UserDao.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">
<mapper namespace="com.test.dao.UserDao">
    <select id="findAll" resultType="com.test.pojo.User">
        select * from user
    </select>
    
    <insert id="save" parameterType="com.test.pojo.User">

        <!--配置添加数据后，获取该条数据的自增id，并封装到对象中-->
        <selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER">
            select last_insert_id();
        </selectKey>
        insert into user(userName,address,sex,birthday)values (#{userName},#{address},#{sex},#{birthday})
    </insert>
</mapper>

5. Mybatis配置文件（SqlMapConfig.xml）

<?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>
    <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:///mybatis_test"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/test/dao/UserDao.xml"/>
        <!--<mapper class="com.test.dao.UserDao"/>-->
        <!--<package name="mapper"/>-->
    </mappers>
</configuration>

6.编写测试类测试

测试目录结构

1. 读取配置文件
2. 创建SqlSessionFactory工厂
3. 使用工厂生产SqlSession对象
4. 使用SqlSession创建Dao接口的代理对象
5. 使用代理对象执行方法
6. 释放资源

MybatisTest.java

package com.test;

import com.test.dao.UserDao;
import com.test.pojo.User;
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.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

public class MybatisTest {

    private InputStream in;
    private SqlSession sqlSession;
    private UserDao userDao;

    @Before
    public void init() throws IOException {
        //1. 读取配置文件
        in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2. 创建SqlSessionFactory工厂
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        SqlSessionFactory factory = builder.build(in);
        //3. 使用工厂生产SqlSession对象
        sqlSession = factory.openSession();
        //4. 使用SqlSession创建Dao接口的代理对象
        userDao = sqlSession.getMapper(UserDao.class);
    }

    @After
    public void destroy() throws IOException {
        //提交事务
        sqlSession.commit();
        //6. 释放资源
        sqlSession.close();
        in.close();
    }

    @Test
    public void testSelect() throws IOException {

        //5. 使用代理对象执行方法
        List<User> userList = userDao.findAll();
        for (User u : userList
        ) {
            System.out.println(u);
        }
    }

    @Test
    public void testSave() throws IOException {

        User u = new User();
        u.setAddress("BJ");
        u.setBirthday(new Date());
        u.setSex("男");
        u.setUserName("HH");
        //5. 使用代理对象执行方法
        userDao.save(u);
    }
}

测试结果

控制台
数据库