1 - 搭建环境

一.单独使用Mybaits

项目结构图--基于maven
jar包
测试:junit
数据库驱动: mysql-connector-java
Mybatis: mybatis
log4j: log4j-core log4j-api
1.创建db,properties

database.driver=com.mysql.jdbc.Driver
database.url=jdbc:mysql://localhost:3306/dbName?serverTimezone=UTC 
database.username=root
database.password=***

2.配置mybatis.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>
    <!--要注意该文件的节点顺序，否则会报错-->
    <!--引入属性文件-->
    <properties resource="db.properties"/>
    <settings>
        <!--配置日志,固定写法-->
        <setting name="logImpl" value="LOG4J2"></setting>
    </settings>
    <!--给实体取别名-->
    <typeAliases>
        <package name="dao"/>
        <package name="model"/>
    </typeAliases>
    <!--数据源配置-->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${database.driver}"/>
                <property name="url" value="${database.url}"/>
                <property name="username" value="${database.username}"/>
                <property name="password" value="${database.password}"/>
            </dataSource>
        </environment>
    </environments>
    <!--引入mapple文件-->
    <mappers >
        <mapper resource="mapple/studentMapple.xml"/>
    </mappers>
</configuration>

3.日志

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Appenders>
        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>
    </Appenders>

    <Loggers>
        <!--过滤掉spring和mybatis的一些无用的DEBUG信息-->
        <logger name="org.springframework" level="INFO"></logger>
        <logger name="org.mybatis" level="INFO"></logger>
        <root level="debug">
            <appender-ref ref="console"/>
        </root>
    </Loggers>
</Configuration>

4.dao和model

package dao;

import model.Student;

import java.util.List;

public interface StudentMapper {
    List<Student> selectAllStudent();
}


package model;

public class Student {
    private int id;
    private String name;
    private int age;

    public Student() {
    }

    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    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 int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

5.mapple

<?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="dao.StudentMapper">
    <select id="selectAllStudent" resultType="student">
      select * from `student`
    </select>
</mapper>

6.测试

import dao.StudentMapper;
import model.Student;
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.Before;
import org.junit.Test;

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

public class AppTest {

    SqlSessionFactory factory = null;

    @Before
    public void prepare() throws IOException{
        InputStream inputStream = Resources.getResourceAsStream("mybatis.xml");
        factory = new SqlSessionFactoryBuilder().build(inputStream);
        inputStream.close();
    }

    @Test
    public void test(){

        SqlSession session=  factory.openSession();
        try{
            StudentMapper studentMapper = session.getMapper(StudentMapper.class);

            List<Student> list = studentMapper.selectAllStudent();
            Iterator<Student> iterator = list.iterator();
            while(iterator.hasNext()){
                Student student = iterator.next();
                System.out.println(student);
            }
        }finally{
            session.commit();
            session.close();
        }
    }
}