SSM复习流程之第一个SM程序

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1、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】

<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>

2、代码实现

回忆MyBatis

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
}

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>

UserDao接口编写

public interface UserMapper {
   public List<User> selectUser();
}

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>

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();
}

整合实现一

1、引入Spring配置文件beans.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">

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、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"/>
   <!--Mybatis中的mapper映射 -->
   <property name="mapperLocations" value="classpath:com/kuang/dao/*.xml"/>
</bean>

4、注册sqlSessionTemplate,关联sqlSessionFactory;

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

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();
  }
   
}

6、注册bean实现

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

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>

整合实现二

mybatis-spring1.2.3版以上的才有这个 .

1、将我们上面写的UserDaoImpl修改一下

public class UserDaoImpl extends SqlSessionDaoSupport implements UserMapper {
   public List<User> selectUser() {
   UserMapper mapper = getSqlSession().getMapper(UserMapper.class);
   return mapper.selectUser();
  }
}

2、修改bean的配置

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

3、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);
}

总结 : spring接管了Mybatis配置文件:数据库信息,sqlSession(不需要建立Mybatis工具类)。Spring一切皆对象bean,所以整合的原理在于把Mybatis转换为bean