• Spring和MyBatis整合时，MyBatis的事务是自动提交的

项目架构

第一步 创建做为数据载体的domain

public class Student {
    public String id;
    public String name;
    public int age;
    public String sex;

    public Student() {
    }

    public Student(String id, String name, int age, String sex) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public void setId(String id) {
        this.id = id;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }
}

第二步 创建与数据交互的dao对象

public interface StudentDao {
    List<Student> selectAll();
}

创建对象的同时完成 dao.xml 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="dao.StudentDao">

    <select id="selectAll" resultType="domain.Student">
        select * from student;
    </select>

</mapper>

第三步 创建service接口和对象
service接口

public interface StudentService {
    void selectAll();
}

接口实现类

public class StudentServiceImpl implements StudentService {
    private StudentDao studentDao;

    public void setStudentDao(StudentDao studentDao){
        this.studentDao = studentDao;
    }

    public void selectAll(){
        System.out.println("Executing selectAll-----------------------");
        List<Student> students = studentDao.selectAll();
        for(Student stu:students){
            System.out.println(stu.name);
        }
    }
}

第四步 创建MyBatis主配置文件

<?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>

    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/><!--开启日志-->
    </settings>

    <typeAliases>
        <package name="dao"/>
    </typeAliases>

    <mappers>
        <package name="dao"/>
    </mappers>
</configuration>

第五步 创建spring的配置文件:声明mybatis的对象交给spring创建

1. 数据源Datasource
2. SqlSessionFactory
3. Dao对象
4. 声明自定义的service

<?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 https://www.springframework.org/schema/context/spring-context.xsd">

    <!--引入配置文件-->
    <context:property-placeholder location="jdbc.properties"/>

    <!--Druid连接池-->
    <bean id="myDateSource" class="com.alibaba.druid.pool.DruidDataSource"
          init-method="init" destroy-method="close">
        <!--连接池配置信息-->
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="maxActive" value="${jdbc.maxActive}"/>
    </bean>

    <!--SqlSessionFactory对象-->
    <bean id="mySqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--赋值 连接池和MyBatis主配置文件-->
        <property name="dataSource" ref="myDateSource"/>
        <property name="configLocation" value="classpath:Mybatis.xml"/>
    </bean>

    <!--创建dao对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--sqlSessionFactory赋值-->
        <property name="sqlSessionFactoryBeanName" value="mySqlSessionFactory"/>
        <!--将dao包下所有dao对象交给Spring容器管理-->
        <property name="basePackage" value="dao"/>
    </bean>
    
    <!--创建service对象-->
    <bean id="myStudentService" class="service.impl.StudentServiceImpl">
        <property name="studentDao" ref="studentDao"/>
    </bean>
</beans>

第六步 创建测试类

public class myTest {
    @Test
    public void test01(){
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        StudentService service = (StudentService) ac.getBean("myStudentService");
        service.selectAll();
    }
}

总结：项目流程就是创建好Spring 容器，Dao对象等，然后通过获取代表Spring容器的ApplicationContext对象，通过该对象获取service对象通过service.selectAll() 进行业务的进行，而在service中会获取与数据库交互的StudentDao，然后对数据库的数据进行查询，并返回。