如何“优雅”的将Spring与Mybatis整合（xml方式）

@[TOC]
思路：
SqlSessionFactory -> SqlSession ->StudentMapper ->CRUD
Spring整合Mybatis时，我们如果只需要SqlSessionFactory 那么其他的功能都是可以实现的，所以在整合时就是将Mybatis的SqlSessionFactory 交给Spring的Ioc容器来管理。

项目的结构图：
在这里插入图片描述
整合的步骤：

1.炸包

mybatis-spring.jar
spring-tx.jar
spring-jdbc.jar
spring-expression.jar
spring-context-support.jar
spring-core.jar
spring-context.jar
spring-beans.jar
spring-aop.jar
spring-web.jar
commons-logging.jar
commons-dbcp.jar
mysql-connector-java.jar
mybatis.jar
log4j.jar
commons-pool.jar

当然，大家也可以用Maven添加依赖：

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <spring.version>5.0.3.RELEASE</spring.version>
    <mybatis.version>3.4.4</mybatis.version>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>
   <dependencies>
    <!--单元测试-->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <!-- 第一部分：Spring 配置-->
    <!-- Spring core -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- Spring DAO -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- Spring mvc -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!-- 数据库 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.38</version>
    </dependency>
    <!-- 数据库连接池 -->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.2</version>
    </dependency>
    <!-- MyBatis -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>${mybatis.version}</version>
    </dependency>
    <!-- mybatis-spring整合包 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.1</version>
    </dependency>
    <!-- 第四部分：日志 -->
    <!--日志-->
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.1.1</version>
    </dependency>
    <dependency>
			<groupId>commons-dbcp</groupId>
			<artifactId>commons-dbcp</artifactId>
			<version>1.4</version>
		</dependency>
        <!--依赖的jar-->
        <dependency>
            <groupId>commons-pool</groupId>
            <artifactId>commons-pool</artifactId>
            <version>1.5.4</version>
        </dependency>
  </dependencies>

2.类-表

在这里插入图片描述

Student

public class Student {

    private int stuNo;
    private String stuName;
    private int stuAge;
	
	//getter,setter....
}

3.Mybatis配置文件：conf.xml

1
2

4.通过mapper.xml将类、表建立映射关系

5.在Spring配置文件中配，SqlSessionFactoy和数据源

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <!--加载配置文件-->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <!--第二种-->
    <!--<bean id="config" class="org.springframework.beans.factory.config.PreferencesPlaceholderConfigurer">-->
        <!--<property name="locations">-->
            <!--<array>-->
                <!--<value>classpath:jdbc.properties</value>-->
            <!--</array>-->
        <!--</property>-->
    <!--</bean>-->
    <!-- 配置数据库信息（替代mybatis的配置文件conf.xml）-->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="${driver}"></property>
        <property name="url" value="${url}"></property>
        <property name="username" value="${username}"></property>
        <property name="password" value="${password}"></property>
        <property name="maxActive" value="${maxActive}"></property>
        <property name="maxIdle" value="${maxIdle}"></property>
    </bean>

    <!-- 在Spring中创建SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--引用配置好的数据源-->
        <property name="dataSource" ref="dataSource"></property>
        <!--加载mybatis的配置文件-->
        <property name="configLocation" value="classpath:config.xml"></property>
    </bean>
</beans>

jdbc.properties
1
2
3
4
5
6
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=true
username=root
password=
maxIdle=1000
maxActive=500
6.使用Spring-MyBatis整合产物开发程序
目标：

通过spring产生mybatis最终操作需要的动态mapper对象(StudentMapper对象）
Spring产生动态mapper对象有3种方法：

a.Dao层实现类继承 SqlSessionDaoSupport类

SqlSessionDaoSupport类提供了一个属性：SqlSession
在这里插入图片描述

StudentMapper

public interface StudentMapper {
    
    public void addStudent(Student student);
    
}

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.itt.mapper.StudentMapper">

    <insert id="addStudent" parameterType="Student">
      insert into student22(stuno,stuname,stuage)
      values(#{stuNo},#{stuName},#{stuAge})
    </insert>

</mapper>

StudentDaoImpl

public class StudentDaoImpl extends SqlSessionDaoSupport implements StudentMapper {
    public void addStudent(Student student) {
        //从父类中获取到sqlSession对象
        SqlSession session = super.getSqlSession();
        StudentMapper studentDao = session.getMapper(StudentMapper.class);
        studentDao.addStudent(student);

    }
}

StudentServiceImpl

1	public class StudentServiceImpl implements IStudentService {

private StudentMapper studentMapper;

public void setStudentMapper(StudentMapper studentMapper) {
    this.studentMapper = studentMapper;
}

public void addStudent(Student student) {
    //调用dao
    studentMapper.addStudent(student);
}

}

* IStudentService
```java
public interface IStudentService {
    
    public void addStudent(Student student);
    
}

config.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="com.itt"/>
    </typeAliases>
    <!-- 数据库的相关信息
        交给Spring来创建
    -->

    <!-- 加载映射文件studentMapper.xml-->
    <mappers>
        <mapper resource="com/itt/mapper/StudentMapper.xml"></mapper>
    </mappers>

</configuration>

AppTest

@Test
    public void demo1(){

        ClassPathXmlApplicationContext applicationContext =
                new ClassPathXmlApplicationContext("applicationContext.xml");
        IStudentService studentService =
                applicationContext.getBean("studentService",IStudentService.class);

        Student student = new Student();
        student.setStuAge(20);
        student.setStuNam("hk");
        student.setStuNo(100);
        studentService.addStudent(student);
    }

运行成功！*
数据也到了库中！*
这样就实现了Spring-Mybatis的整合！*
此方法的改进：
可以将config.xml文件中的加载映射文件studentMapper.xml也交给Spring来加载，代码如下：

注意：*
使用mybatis时，增删改时必须手动提交事务！
在使用Spring时，默认自动提交事务！

b.第二种方式，就是去掉第一种方式的dao的实现类

Mybatis已经给我们实现了功能，我们只需要注册容器并注入接口位置与SqlSessionfactory就可以了！
在这里插入图片描述

这样的方式也是可以实现业务的！
但是这有一个缺点，那就是每生成一个Mapper对象就得配置一次，太过于麻烦！

C.批量配置实现类

使用mybatis-spring提供的：org.mybatis.spring.mapper.MapperScannerConfigurer批量扫描配置文件

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    <!--加载配置文件-->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <!--第二种-->
    <!--<bean id="config" class="org.springframework.beans.factory.config.PreferencesPlaceholderConfigurer">-->
        <!--<property name="locations">-->
            <!--<array>-->
                <!--<value>classpath:jdbc.properties</value>-->
            <!--</array>-->
        <!--</property>-->
    <!--</bean>-->

    <!-- 第一种方式生成mapper对象
    <bean id="studentMapper" class="com.itt.dao.impl.StudentDaoImpl">-->
        <!--&lt;!&ndash; 将Spring配置好的SqlSessionFactory交给mapper(dao)&ndash;&gt;-->
        <!--<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>-->
    <!--</bean>-->

    <!-- 第二种方式：生成mapper对象-->
    <!--<bean id="studentMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">-->
        <!--<property name="mapperInterface" value="com.itt.mapper.StudentMapper"></property>-->
        <!--<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>-->
    <!--</bean>-->
    <!-- 第三种方式，生mapper对象（批量方式）
        批量产生对在SpringIOC中的id值默认就是接口名
    -->
    <bean id="mappers" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
        <!--指定批量产生哪个包中的mapper对象-->
        <property name="basePackage" value="com.itt.mapper"/>
    </bean>

    <bean id="studentService" class="com.itt.service.impl.StudentServiceImpl">
        <property name="studentMapper" ref="studentMapper"></property>
    </bean>


    <!-- 配置数据库信息（替代mybatis的配置文件conf.xml）-->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="${driver}"></property>
        <property name="url" value="${url}"></property>
        <property name="username" value="${username}"></property>
        <property name="password" value="${password}"></property>
        <!--<property name="maxActive" value="${maxActive}"></property>-->
        <!--<property name="maxIdle" value="${maxIdle}"></property>-->
    </bean>

    <!-- 在Spring中创建SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--引用配置好的数据源-->
        <property name="dataSource" ref="dataSource"></property>
        <!--加载mybatis的配置文件-->
        <property name="configLocation" value="classpath:config.xml"></property>
        <!-- 扫描sql配置文件:mapper需要的xml文件 -->
        <property name="mapperLocations" value="com/itt/mapper/*.xml"></property>
    </bean>
</beans>