上一節介紹了jdbcTemplate,但是它的手動映射讓人感覺很麻煩,這節主要講述Spring提供的另一種dao層解決方案,即使用Spring-Mybatis整合框架,這也是我學的第一個整合框架;
整合的思路:將SqlSessionFactory交給Spring管理;
使用步驟:
- 引入依賴;
- 創建bean類,dao層、service層、controller層相關的類;
- 創建Mybatis的xml配置文件、Mapper的配置文件、Spring的配置文件;
- 使用;
一 、引入依賴
需要引入Spring-Mybatis整合的依賴包、和Mybatis的依賴包,(當然,還有Spring的基本依賴包,前面說過,這隻寫需要新添加的):
<!--mybatis和spring整合包-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.0</version>
</dependency>
<!--mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.1</version>
</dependency>
Student表如下:
第一種方式
先來介紹這一種:
二、創建相關的類
創建對應的bean類:
public class Student {
private int id;
private String name;
private String sex;
private int 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 String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", name='" + name + '\'' +
", sex='" + sex + '\'' +
", age=" + age +
'}';
}
}
Mapper接口:
public interface StudentMapper {
public Student getStudentById(int id);
}
dao層對象:
public class StudentDao {
private SqlSessionFactory sqlSessionFactory;
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
this.sqlSessionFactory = sqlSessionFactory;
}
public Student getStudentBean(int id) {
//獲取sqlSession實例
SqlSession sqlSession = sqlSessionFactory.openSession();
Student student = (Student) sqlSession.selectOne("com.tulun6.dao.StudentMapper.getStudentById", id);
return student;
}
}
這個dao層類還可以這樣寫,更簡單:
public class StudentDao extends SqlSessionDaoSupport {
public Student getStudentBean(int id) {
//獲取sqlSession實例
SqlSession sqlSession = this.getSqlSession();
Student student = (Student) sqlSession.selectOne("com.tulun6.dao.StudentMapper.getStudentById", id);
return student;
}
}
因爲SqlSessionDaoSupport類裏面本身就有SqlSessionFactory屬性,並提供了set方法,所以直接繼承拿人家的用就好了;
service層:
public class StudentService {
private StudentDao studentDao;
public void setStudentDao(StudentDao studentDao) {
this.studentDao = studentDao;
}
public Student getStudentBean(int id) {
return studentDao.getStudentBean(id);
}
}
controller層:
public class StudentController {
private StudentService studentService;
public void setStudentService(StudentService studentService) {
this.studentService = studentService;
}
public Student getStudentById(int id) {
return studentService.getStudentBean(id);
}
}
三、創建相關的配置文件
然後就是配置文件,StudentMapper.xml:
<?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.tulun6.dao.StudentMapper">
<select id="getStudentById" parameterType="int" resultType="com.tulun6.bean.Student">
select * from student where id = #{id}
</select>
</mapper>
mybatis的配置文件,mybatis.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>
<!--映射-->
<!--<mappers>
<mapper resource="spring-mybatis整合/StudentMapper.xml"/>
</mappers>-->
</configuration>
其實更多的時候,我們會把映射文件寫在mybatis的配置文件裏面,這樣可以減少對Spring配置文件的依賴,但這一節爲了介紹如何在Spring裏面配置映射,就沒在這兒寫(就是註釋掉的那部分語句,但是要知道,寫在這兒也是可以的,只是Spring關於映射的語句就不能寫了,不然有兩個,它就不知道怎麼辦了,就會報錯),下面就是Spring的配置文件spring-mybatis.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"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--配置數據源 通過連接池c3p0來操作-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<!--配置數據連接的核心配置-->
<property name="driverClass" value="com.mysql.jdbc.Driver"/>
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="user" value="root"/>
<property name="password" value="123456"/>
</bean>
<!--創建SqlSessionFactory對象 路徑是整合包裏面的SqlSessionFactoryBean的全路徑-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--數據庫的連接配置-->
<property name="dataSource" ref="dataSource"/>
<!--配置Mybatis的XML文件的路徑-->
<property name="configLocation" value="classpath:spring-mybatis整合/mybatis.xml"/>
<!--配置Mapper的xml文件-->
<!--================標記==========================-->
<property name="mapperLocations">
<list>
<value>spring-mybatis整合/StudentMapper.xml</value>
</list>
</property>
<!--================標記==========================-->
</bean>
<!--創建Controller層對象-->
<bean id="dao" class="com.tulun6.dao.StudentDao">
<!--注入service層對象作爲屬性-->
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
<!--創建Service層對象-->
<bean id="service" class="com.tulun6.service.StudentService">
<!--注入service層對象作爲屬性-->
<property name="studentDao" ref="dao"/>
</bean>
<!--創建Controller層對象-->
<bean id="controller" class="com.tulun6.controller.StudentController">
<!--注入service層對象作爲屬性-->
<property name="studentService" ref="service"/>
</bean>
</beans>
上面spring的配置文件裏面我打標記的那部分語句和mybatis裏面的映射語句只能存在一個!!
四、使用
public class TestDemo1 {
@Test
public void test() {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-mybatis整合/spring-mybatis.xml");
StudentController studentController = (StudentController)context.getBean("controller");
Student student = studentController.getStudentById(1);
System.out.println(student);
}
}
第二種方式
這種寫法就是使用Mapper代理對象進行映射開發,就像在Mybatis框架裏面一樣,我們要通過SqlSessionFactory最終得到Mapper對象,然後使用一樣:
bean層類不用改,dao層的類也不用改,因爲不用dao層的對象了,service需要改一下(屬性是Mapper接口類型的):
public class StudentService1 {
private StudentMapper studentMapper;
public void setStudentMapper(StudentMapper studentMapper) {
this.studentMapper = studentMapper;
}
public Student getStudentBean(int id) {
return studentMapper.getStudentById(id);
}
}
那對應的controller層類也就需要改一下了:
public class StudentController1 {
private StudentService1 studentService1;
public void setStudentService1(StudentService1 studentService1) {
this.studentService1 = studentService1;
}
public Student getStudentById(int id) {
return studentService1.getStudentBean(id);
}
}
三個配置文件,需要該spring的配置文件(改的是我寫標記的那部分):
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!--配置數據源 通過連接池c3p0來操作-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<!--配置數據連接的核心配置-->
<property name="driverClass" value="com.mysql.jdbc.Driver"/>
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="user" value="root"/>
<property name="password" value="123456"/>
</bean>
<!--創建SqlSessionFactory對象 路徑是整合包裏面的SqlSessionFactoryBean的全路徑-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--數據庫的連接配置-->
<property name="dataSource" ref="dataSource"/>
<!--配置Mybatis的XML文件的路徑-->
<property name="configLocation" value="classpath:spring-mybatis整合/mybatis.xml"/>
<!--配置Mapper的xml文件-->
<property name="mapperLocations">
<list>
<value>spring-mybatis整合/StudentMapper.xml</value>
</list>
</property>
</bean>
<!--===========================標記=========================================-->
<!--使用Mapper代理對象進行映射開發 class即MapperFactoryBean-->
<bean id="studentMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<!--mapperInterface指定mapper接口-->
<property name="mapperInterface" value="com.tulun6.dao.StudentMapper"/>
<!--指定sqlSessionFactory-->
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
<!--創建Service層對象-->
<bean id="service" class="com.tulun6.service.StudentService1">
<!--注入service層對象作爲屬性-->
<property name="studentMapper" ref="studentMapper"/>
</bean>
<!--創建Controller層對象-->
<bean id="controller1" class="com.tulun6.controller.StudentController1">
<!--注入service層對象作爲屬性-->
<property name="studentService1" ref="service"/>
</bean>
<!--===========================標記=========================================-->
</beans>
測試:
public class TestDemo2 {
@Test
public void test() {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-mybatis整合/spring-mybatis-plus.xml");
StudentController1 studentController1 = (StudentController1) context.getBean("controller1");
Student student = studentController1.getStudentById(1);
System.out.println(student);
}
}