MyBatis学习日记（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。