MyBatis案例一:入门

MyBatis案例一:入门

创建maven项目

1. 使用maven project向导创建一个maven项目（不使用骨架，package使用：jar）
2. 配置依赖包：

<dependencies>
  	<!-- https://mvnrepository.com/artifact/junit/junit -->
	<dependency>
		<groupId>junit</groupId>
		<artifactId>junit</artifactId>
		<version>4.12</version>
	</dependency>
	<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
	<dependency>
		<groupId>org.mybatis</groupId>
		<artifactId>mybatis</artifactId>
		<version>3.2.6</version>
	</dependency>
	<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
	<dependency>
	    <groupId>mysql</groupId>
	    <artifactId>mysql-connector-java</artifactId>
	    <version>5.1.6</version>
	</dependency>		
  </dependencies>

3. 配置构建插件

<build>
		<plugins>
			<!-- 资源文件拷贝插件 -->
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-resources-plugin</artifactId>
				<version>2.7</version>
				<configuration>
					<encoding>UTF-8</encoding>
				</configuration>
			</plugin>
			<!-- java编译插件 -->
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.2</version>
				<configuration>
					<source>1.7</source>
					<target>1.7</target>
					<encoding>UTF-8</encoding>
				</configuration>
			</plugin>				
		</plugins>
	</build>

配置SqlMapConfig.xml

1. 在src/main/java下创建mybatis配置文件SqlMapConfig.xml
2. 添加dtd约束

<?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">

3. 配置环境，连接数据库

<configuration>
		<environments default="mysql">
			<environment id="mysql">
				<transactionManager type="jdbc"></transactionManager>
				<dataSource type="pooled">
					<property name="url" value="jdbc:mysql://localhost:3306/hr"/>
					<property name="driver" value="com.mysql.jdbc.Driver"/>
					<property name="username" value="root"/>
					<property name="password" value="root"/>
				</dataSource>
			</environment>
		</environments>
	</configuration>

使用MyBatis

1. 创建com.yy.mapper包、com.yy.domain包（添加实体类Dept）
2. 创建DeptMapper接口文件，添加方法：

public List<Dept> getAll();

3.使用mybatis向导，创建DeptMapper.xml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.yy.mapper.DeptMapper">
	</mapper>

4. 添加查询statement

<select id="getAll" parameterType="com.yy.domain.Dept">
		select * from dept
</select>

5. 在DeptMapper.java文件上右键，使用junit向导，创建单元测试

public class DeptMapperTest {
		@Test
		public void testGetAll() {
			
		}
	}

6. 编写测试方法代码

@Test
	public void testGetAll() throws IOException {
		InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);		
		SqlSession session = factory.openSession();
		DeptMapper deptMapper = session.getMapper(DeptMapper.class);
		session.close();
	}

7. 在SqlMapConfig文件中添加映射文件

<mappers>
	<mapper resource="com/yy/mapper/DeptMapper.xml" />
</mappers>

8. 运行测试（项目右键=》run as=》Maven test），查看控制台显示信息

9. 在DeptMapperTest.java文件上右键，直接运行junit Test也可以测试