环境搭建

在POM.xml中加入依赖

<dependencies>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/log4j/log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/junit/junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

  </dependencies>

db.properties加到/TestMybatis/src/main/resources下

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/javaee?useUnicode=true&characterEncoding=utf8
username=root
password=root

创建SqlMapConfig.xml
说明：
xml约束文档有两类，dtd xsd

<?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>
    <!-- 使用外部的properties文件 -->
    <properties resource="db.properties">

    </properties>
    <!-- 启动延迟加载 -->
    <settings>
        <setting name="lazyLoadingEnabled" value="true" />
        <setting name="aggressiveLazyLoading" value="false" />
    </settings>
    <!-- 定义别名 -->
    <typeAliases>
        <package name="com.neuedu.model.po" />
    </typeAliases>


    <!-- 配置数据库连接的信息 -->
    <environments default="test">
        <environment id="test">
            <transactionManager type="JDBC">

            </transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}" />
                <property name="url" value="${url}" />
                <property name="username" value="${username}" />
                <property name="password" value="${password}" />
            </dataSource>
        </environment>
    </environments>

    <!-- 注册所有的mapper文件 -->
    <!-- 使用package，要求接口和xml在同包下，且名字相同 -->
    <mappers>
        <!-- <mapper resource="com/neuedu/model/mapper/StudentMapper.xml" /> -->
        <package name="com.neuedu.model.mapper" />

    </mappers>


</configuration> 

编写接口文件

package com.neuedu.model.dao;
import java.util.List;
import com.neuedu.model.bo.Suser;
public interface SuserMapper {
    public List<Suser> getAllUsers();
    public void addUser();
    public void deleteUser();
}

编写Mapper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="com.neuedu.model.dao.SuserMapper" >     
   <select id="getAllUsers" resultType="com.neuedu.model.bo.Suser">
       select * from suser
   </select>
   <insert id="addUser">
        insert into suser(name,age) values ('xx',20)
   </insert>  
   <delete id="deleteUser">
        delete from suser where id = 2
   </delete> 
</mapper>

构造方法私有

public class SessionUtils {
    //构造方法私有，外部不能创建对象
    private SessionUtils() {
        
    }
    public static SqlSession getSession() {
        //从ClassPath找SqlMapConfig.xml
        InputStream ins;
        try {
            
            ins = Resources.getResourceAsStream("SqlMapConfig.xml");
            SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(ins);
            //2.通过session工厂获得数据库连接
            SqlSession session=factory.openSession();
            return session;
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;        
    }                       
}

运行测试程序

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        getStudentByPage();
    }
public  void getStudentByPage() {
        // 获得一个Sqlsession
        SqlSession session = SessionUtils.getSession();
        // 通过session得到一个mapper
        StudentMapper studentMapper = session.getMapper(StudentMapper.class);
        // 调用方法
        List<Student> students = studentMapper.getStudentByPage(0,10);
        for (Student a : students) {
            System.out.println(a.getId() + "\t" + a.getStuname() + "\t" + a.getBirthday());
        }
    }

配置log4j, 将log4.propertis 放在classpath跟路径下

# Global logging configuration
log4j.rootLogger=DEBUG,stdout
# MyBatis logging configuration...
log4j.logger.org.mybatis.example.BlogMapper=TRACE
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

结构

笔记很详细呦