MyBatis日记（二）： MyBatis Say Hello

首先在Eclipse中创建一个maven工程：

在maven工程下的pom.xml文件中添加MyBatis、MySQL、Junit依赖：

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.Aiden</groupId>
    <artifactId>MyBatisByRe</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

在MySQL中创建数据库——db_mbre，并建立一个t_student表：

CREATE TABLE `t_student` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) DEFAULT NULL,
  `age` int(10) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

在src文件夹下创建MySQL数据库链接的配置文件——jdbc.properties：

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_mbre
jdbc.username=root
jdbc.password=123456

在src文件夹下创建MyBatis的配置文件——MyBatis-config.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>
    <properties resource="jdbc.properties" />
    <typeAliases>
        <typeAlias alias="Student" type="com.Aiden.domain.Student" />
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driverClassName}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/Aiden/dao/StudentMapper.xml" />
    </mappers>
</configuration>

在src目录下创建com.Aiden.dao、com.Aiden.domain、com.Aiden.service、com.Aiden.util四个包。

在com.Aiden.domain包下创建Student实体文件——Student.java：

package com.Aiden.doamin;
public class Student {
    private Integer id;
    private String name;
    private Integer age;
    public Student() {
        super();
    }
    public Student(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }
    public Student(Integer id, String name, Integer age) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
    }
    
}

在com.Aiden.dao包下创建student的映射接口（StudentMapper.java）以及映射文件（StudentMapper.xml）：

package com.Aiden.dao;
import com.Aiden.doamin.Student;
public interface StudentMapper {
    public int addStudent(Student student);
}

<?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.Aiden.dao.StudentMapper">
    <insert id="addStudent" parameterType="Student">
        insert into t_student values(null,#{name},#{age})
    </insert>
</mapper>

在com.Aiden.util包下创建SqlSession工具类——SqlSessionFactoryUtil.java:

package com.Aiden.util;

import java.io.IOException;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class SqlSessionFactoryUtil {
    public static SqlSessionFactory sqlSessionFactory;
    public static SqlSessionFactory getSqlSessionFactory() {
        if(sqlSessionFactory==null) {
            InputStream inputStream=null;
            try {
                inputStream=Resources.getResourceAsStream("mybatis-config.xml");
                sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return sqlSessionFactory;
    }
    public static SqlSession openSession() {
        return getSqlSessionFactory().openSession();
    }
}

在com.Aiden.service包下创建Junit测试类——MybatisDemo01.java：

package com.Aiden.service;

import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.Aiden.dao.StudentMapper;
import com.Aiden.domain.Student;
import com.Aiden.util.SqlSessionFactoryUtil;

public class MybatisDemo02 {
    private static SqlSession sqlSession=null;
    private static StudentMapper studentMapper=null;

    @Before
    public void setUp() throws Exception {
        sqlSession=SqlSessionFactoryUtil.openSession();
        studentMapper=sqlSession.getMapper(StudentMapper.class); 
    }

    @After
    public void tearDown() throws Exception {
        sqlSession.close();
    }

    @Test
    public void testAddStudent() {
        Student student=new Student("苍井空", 26);
        studentMapper.addStudent(student);
        sqlSession.commit();
    }

}

运行测试方法testAddStudent。插入数据成功。