MyBatis 初试~

以前用过iBatis，今天学习了一下MyBatis的用法

 

1、依赖配置

 

 项目为Maven搭建，相关依赖如下

 

<dependencies>
	<dependency>
		<groupId>junit</groupId>
		<artifactId>junit</artifactId>
		<version>4.11</version>
		<scope>test</scope>
	</dependency>
	<dependency>
		<groupId>org.mybatis</groupId>
		<artifactId>mybatis</artifactId>
		<version>3.2.3</version>
	</dependency>
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>5.1.27</version>
	</dependency>
</dependencies>

 

 

2、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="com.mysql.jdbc.Driver" />
				<property name="url" value="jdbc:mysql://xxx:3306/lb_test" />
				<property name="username" value="root" />
				<property name="password" value="xxx" />
			</dataSource>
		</environment>
	</environments>
	<mappers>
		<mapper resource="com/leibo/vo/UserMapper.xml" />
	</mappers>
</configuration>

 

3、实体类

 

public class User {

	private int id;

	private String name;

	private int age;

	/**
	 * 必须要有默认构造函数
	 */
	public User(){
		
	}
	
	public User(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;
	}

}

 

4、MyBatis的SQL映射文件

 

<?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.leibo.vo">
	<select id="selectUsers"  resultType="com.leibo.vo.User">
		select * from user
	</select>
	
	<insert id="insertUser" parameterType="com.leibo.vo.User" useGeneratedKeys="true" keyProperty="id">
		insert into user(name,age) values (#{name},#{age})
	</insert>
	
	<delete id="deleteUser" parameterType="int">
		delete from user where id = #{id}
	</delete>
	
	<update id="updateUser" parameterType="java.util.Map">
		update user set name = #{name} where id = #{id}
	</update>
	
</mapper>

 

5、单元测试

 

   仅仅为测试用法，代码写的不是很规范

public class UserTest {

	SqlSessionFactory sqlSessionFactory = null;

	@Before
	public void setUp() throws Exception {
		String resource = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
	}

	@Test
	public void query() {
		SqlSession sqlSession = sqlSessionFactory.openSession();
		List<User> list = sqlSession.selectList("selectUsers");
		for (User user : list) {
			System.out.println(user.getName() + " -> " + user.getAge());
		}
		sqlSession.close();
	}

	@Test
	public void insert() {
		SqlSession sqlSession = sqlSessionFactory.openSession();
		User user = new User("insert1", 22);
		sqlSession.insert("insertUser", user);
		// 必须要写提交，不然不会插入数据
		sqlSession.commit();
		sqlSession.close();
	}

	@Test
	public void delete() {
		SqlSession sqlSession = sqlSessionFactory.openSession();
		sqlSession.delete("deleteUser", 6);
		sqlSession.commit();
		sqlSession.close();
	}

	@Test
	public void update() {
		SqlSession sqlSession = sqlSessionFactory.openSession();
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("name", "new name");
		map.put("id", 7);
		sqlSession.update("updateUser", map);
		sqlSession.commit();
		sqlSession.close();
	}

}