接着上章内容mybatis源码环境搭建,根据官方文档，运行一个demo项目。
项目结构
- 项目源代码:mybatis-learning-01
mybatis-learning/mybatis-learning-01
├── mybatis-learning-01.iml
├── pom.xml #项目依赖管理 1
└── src
├── main
│ ├── java
│ │ ├── cn
│ │ │ └── z201
│ │ │ └── mybatis
│ │ │ └── learning
│ │ │ ├── SetUpSessionFactory.java # mybatis 初始化 3
│ │ │ ├── User.java # 实体 5
│ │ │ └── UserDao.java # 实体dao 6
│ │ └── package-info.java
│ └── resources
│ ├── init_table.sql # h2数据库初始化sql 4
│ ├── mybatis
│ │ └── UserDao.xml # dao 对应的mapper 7
│ └── mybatis-config.xml # mybatis 配置文件 2
└── test
└── java
└── cn
└── z201
└── mybatis
└── test
├── MybatisTest01.java # 单元测试 8
└── package-info.java
15 directories, 11 files
根据上面注释的顺序，我们依次介绍项目代码。
0x01 项目依赖管理
<?xml version="1.0" encoding="UTF-8"?>
<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>cn.z201</groupId>
<artifactId>mybatis-learning-01</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>8</source>
<target>8</target>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<mybatis.version>3.5.0</mybatis.version>
<junit.version>4.12</junit.version>
<lmbok.version>1.18.4</lmbok.version>
<mysql.version>5.1.47</mysql.version>
<h2.version>1.4.197</h2.version>
<!-- pom文件需要指定打包编码集，[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>${mybatis.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lmbok.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>${h2.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
0x02 mybatis 配置文件
<?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="org.h2.Driver"/>
<property name="url" value="jdbc:h2:mem:mybatis_learning_01_db;MODE=MYSQL;INIT=RUNSCRIPT FROM './src/main/resources/init_table.sql'"/>
<property name="username" value="root"/>
<property name="password" value=""/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mybatis/UserDao.xml"/>
</mappers>
</configuration>
0x03 mybatis 初始化
package cn.z201.mybatis.learning;
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 java.io.IOException;
import java.io.InputStream;
public class SetUpSessionFactory {
public SqlSession initSessionFactory() throws IOException {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
return sqlSessionFactory.openSession();
}
}
0x04 h2数据库初始化sql
CREATE TABLE `user`(
id SMALLINT PRIMARY KEY AUTO_INCREMENT ,
name VARCHAR(50),
age SMALLINT,
gender SMALLINT
);
INSERT INTO `user`(name , age , gender) VALUES('TOM' , 12 , 0 );
INSERT INTO `user`(name , age , gender) VALUES('JON' , 13 , 1 );
INSERT INTO `user`(name , age , gender) VALUES('King' , 11 , 0 );
0x05 实体bean
package cn.z201.mybatis.learning;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.ToString;
@Data
@AllArgsConstructor
@ToString
public class User {
private Integer id;
private String name;
private Integer age;
private Integer gender;
}
0x06 实体dao
package cn.z201.mybatis.learning;
import java.util.List;
public interface UserDao {
List<User> list();
}
0x07 实体dao对应的mapper.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="cn.z201.mybatis.learning.UserDao">
<select id="list" resultType="cn.z201.mybatis.learning.User">
SELECT * FROM `user`
</select>
</mapper>
0x08 单元测试
package cn.z201.mybatis.test;
import cn.z201.mybatis.learning.SetUpSessionFactory;
import cn.z201.mybatis.learning.User;
import cn.z201.mybatis.learning.UserDao;
import org.apache.ibatis.session.SqlSession;
import org.junit.Assert;
import org.junit.Test;
import java.io.IOException;
import java.util.List;
public class MybatisTest01 {
@Test
public void test01() throws IOException {
SetUpSessionFactory setUpSessionFactory = new SetUpSessionFactory();
SqlSession sqlSession = setUpSessionFactory.initSessionFactory();
UserDao userDao = sqlSession.getMapper(UserDao.class);
List<User> userList = userDao.list();
sqlSession.close();
Assert.assertNotNull(userList);
userList.forEach(System.out::println);
}
}
- 结果
User(id=1, name=TOM, age=12, gender=0)
User(id=2, name=JON, age=13, gender=1)
User(id=3, name=King, age=11, gender=0)