从0开始整合SSM框架--2.spring整合mybatis

依赖:
<properties>
<!-- spring版本号 -->
<spring.version>4.1.3.RELEASE</spring.version>
</properties>

<!-- Spring依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-oxm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<!--数据库连接池-->
<dependency>
<groupId>com.mchange</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.5.2</version>
</dependency>
<!--Spring+mybatis的整合包-->
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.2</version>
</dependency>

整合的步骤
　　第一步：创建一个java工程。
　　第二步：导入jar包。（上面提到的jar包）
　　第三步：mybatis的配置文件sqlmapConfig.xml
　　第四步：编写Spring的配置文件
　　　　1、数据库连接及连接池
　　　　2、事务管理（暂时可以不配置）
　　　　3、sqlsessionFactory对象，配置到spring容器中
　　　　4、mapeer代理对象或者是dao实现类配置到spring容器中。
　　第五步：编写dao或者mapper文件
　　第六步：测试。

SqlMapConfig.xml

<?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="cn.itcast.mybatis.pojo"/>
　　</typeAliases>
<mappers>
　　<mapper resource="sqlmap/User.xml"/>
</mappers>
</configuration>

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
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-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:db.properties" />
<!-- 数据库连接池 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxActive" value="10" />
<property name="maxIdle" value="5" />
</bean>
<!-- mapper配置 -->
<!-- 让spring管理sqlsessionfactory 使用mybatis和spring整合包中的 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 数据库连接池 -->
<property name="dataSource" ref="dataSource" />
<!-- 加载mybatis的全局配置文件 -->
<property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml" />
</bean>

</beans>

db.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
jdbc.username=root
jdbc.password=root

1.Dao的开发
三种dao的实现方式：
　　1、传统dao的开发方式
　　2、使用mapper代理形式开发方式
　　3、使用扫描包配置mapper代理。

 传统dao的开发方式

接口+实现类来完成。需要dao实现类需要继承SqlsessionDaoSupport类

public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {

@Override
public User findUserById(int id) throws Exception {
SqlSession session = getSqlSession();
User user = session.selectOne("test.findUserById", id);
//不能关闭SqlSession，让spring容器来完成
//session.close();
return user;
}

@Override
public void insertUser(User user) throws Exception {
SqlSession session = getSqlSession();
session.insert("test.insertUser", user);
session.commit();
//session.close();
}

}

配置dao
把dao实现类配置到spring容器中
<!-- 配置UserDao实现类 -->
<bean id="userDao" class="cn.itcast.dao.UserDaoImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
测试方法
@Test
public void testFindUserById() throws Exception {
UserDao userDao = (UserDao) applicationContext.getBean("userDao");
User user = userDao.findUserById(1);
System.out.println(user);
}

2.Mapper代理形式开发dao
开发mapper接口

在applicationContext中配置mapper代理

<!-- 配置mapper代理对象 -->
<bean class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="mapperInterface" value="cn.itcast.mybatis.mapper.UserMapper"/>
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>

测试方法
public class UserMapperTest {

private ApplicationContext applicationContext;
@Before
public void setUp() throws Exception {
applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
}

@Test
public void testGetUserById() {
UserMapper userMapper = applicationContext.getBean(UserMapper.class);
User user = userMapper.getUserById(1);
System.out.println(user);
}

}

扫描包形式配置mapper
<!-- 使用扫描包的形式来创建mapper代理对象 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="cn.itcast.mybatis.mapper"></property>
</bean>
每个mapper代理对象的id就是类名，首字母小写

测试
public class mybatisTest {
private ApplicationContext applicationContext;
@Before
public void setUp() throws Exception {
applicationContext = new ClassPathXmlApplicationContext("Spring/applicationContext.xml");
}

@Test
public void testFindUserById() throws Exception {
UserDao userDao = (UserDao) applicationContext.getBean("userDao");
User user = userDao.findUserById(10);
System.out.println(user);

}
}