OwensonSun

 

① 回忆mybatis

  1. 编写pojo实体类
package com.kuang.pojo;

public class User {
   private int id;  //id
   private String name;   //姓名
   private String pwd;   //密码
}
  1. 实现mybatis的配置文件
<?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>

   <typeAliases>
       <package name="com.kuang.pojo"/>
   </typeAliases>

   <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://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf8"/>
               <property name="username" value="root"/>
               <property name="password" value="123456"/>
           </dataSource>
       </environment>
   </environments>

   <mappers>
       <package name="com.kuang.dao"/>
   </mappers>
</configuration>
  1. UserDao接口编写
public interface UserMapper {
   public List<User> selectUser();
}
  1. 接口对应的Mapper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.kuang.dao.UserMapper">

   <select id="selectUser" resultType="User">
    select * from user
   </select>

</mapper>
  1. 测试类
@Test
public void selectUser() throws IOException {

   String resource = "mybatis-config.xml";
   InputStream inputStream = Resources.getResourceAsStream(resource);
   SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
   SqlSession sqlSession = sqlSessionFactory.openSession();

   UserMapper mapper = sqlSession.getMapper(UserMapper.class);

   List<User> userList = mapper.selectUser();
   for (User user: userList){
       System.out.println(user);
  }

   sqlSession.close();
}

② 整合步骤

整合实现方法一:

  1. 引入Spring之前需要了解mybatis-spring包中的一些重要类;

    http://www.mybatis.org/spring/zh/index.html

    如果使用 Maven 作为构建工具,仅需要在 pom.xml 中加入以下代码即可:

    <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis-spring</artifactId>
       <version>2.0.2</version>
    </dependency>
    
  2. 导入相关jar包

junit

<dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>4.12</version>
</dependency>

mybatis

<dependency>
   <groupId>org.mybatis</groupId>
   <artifactId>mybatis</artifactId>
   <version>3.5.2</version>
</dependency>

mysql-connector-java

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>5.1.47</version>
</dependency>

spring相关

<dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-webmvc</artifactId>
   <version>5.1.10.RELEASE</version>
</dependency>
<dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-jdbc</artifactId>
   <version>5.1.10.RELEASE</version>
</dependency>

aspectJ AOP 织入器

<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
<dependency>
   <groupId>org.aspectj</groupId>
   <artifactId>aspectjweaver</artifactId>
   <version>1.9.4</version>
</dependency>

mybatis-spring整合包 【重点】xml

<dependency>
   <groupId>org.mybatis</groupId>
   <artifactId>mybatis-spring</artifactId>
   <version>2.0.2</version>
</dependency>

配置Maven静态资源过滤问题!

<build>
   <resources>
       <resource>
           <directory>src/main/java</directory>
           <includes>
               <include>**/*.properties</include>
               <include>**/*.xml</include>
           </includes>
           <filtering>true</filtering>
       </resource>
   </resources>
</build>
  1. 编写配置文件

    3.1 引入spring配置文件 xxx.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd">
    

    3.2 配置数据源替换mybaits的数据源

<!--配置数据源:数据源有非常多,可以使用第三方的,也可使使用Spring的-->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
   <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
   <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf8"/>
   <property name="username" value="root"/>
   <property name="password" value="123456"/>
</bean>

​ 3.3 配置SqlSessionFactory,关联MyBatis

<!--配置SqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
   <property name="dataSource" ref="dataSource"/>
   <!--关联Mybatis-->
   <property name="configLocation" value="classpath:mybatis-config.xml"/>
   <property name="mapperLocations" value="classpath:com/kuang/dao/*.xml"/>
</bean>

​ 3.4 注册sqlSessionTemplate,关联sqlSessionFactory;

<!--注册sqlSessionTemplate , 关联sqlSessionFactory-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
   <!--只能用利用构造器注入,没有set方法-->
   <constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

3.5 增加Dao接口的实现类;私有化sqlSessionTemplate

public class UserDaoImpl implements UserMapper {

   //sqlSession不用我们自己创建了,Spring来管理
   private SqlSessionTemplate sqlSession;

   public void setSqlSession(SqlSessionTemplate sqlSession) {
       this.sqlSession = sqlSession;
  }

   public List<User> selectUser() {
       UserMapper mapper = sqlSession.getMapper(UserMapper.class);
       return mapper.selectUser();
  }
   
}

3.6 注册bean实现

<bean id="userDao" class="com.kuang.dao.UserDaoImpl">
   <property name="sqlSession" ref="sqlSession"/>
</bean>

3.7 测试

   @Test
   public void test2(){
       ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
       UserMapper mapper = (UserMapper) context.getBean("userDao");
       List<User> user = mapper.selectUser();
       System.out.println(user);
  }

结果成功输出!现在我们的Mybatis配置文件的状态!发现都可以被Spring整合!

<?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>
   <typeAliases>
       <package name="com.kuang.pojo"/>
   </typeAliases>
</configuration>

整合实现方法二:

除了对sqlSessionTemplate的配置不同外,其余与方法一一致。具体如下:

SqlSessionDaoSupport 是一个抽象的支持类,用来为你提供 SqlSession。调用 getSqlSession() 方法你会得到一个 SqlSessionTemplate,之后可以用于执行 SQL 方法,就像下面这样:

public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {
  public User getUser(String userId) {
    return getSqlSession().getMapper(UserMapperImpl.class).selectUser();
  }
}

在这个类里面,通常更倾向于使用 MapperFactoryBean,因为它不需要额外的代码。但是,如果你需要在 DAO 中做其它非 MyBatis 的工作或需要一个非抽象的实现类,那么这个类就很有用了。

SqlSessionDaoSupport 需要通过属性设置一个 sqlSessionFactory 或 SqlSessionTemplate。如果两个属性都被设置了,那么 SqlSessionFactory 将被忽略。

假设类 UserMapperImpl 是 SqlSessionDaoSupport 的子类,可以编写如下的 Spring 配置来执行设置:

<bean id="userDao" class="org.mybatis.spring.sample.dao.UserDaoImpl">
  <property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>

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