Spring与Mybatis的整合

提供一种Spring的IoC容器与Mybatis的整合方式，其中中，Mybatis采用纯注解方式配置，Spring采用XML方式配置。数据库源采用的是C3P0数据库连接池。

1. 在Spring的XML配置文件中添加相关配置

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    <property name="driverClass" value="com.mysql.cj.jdbc.Driver"/>
    <property name="jdbcUrl"
              value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true"/>
    <property name="user" value="root"/>
    <property name="password" value="password123"/>
</bean>
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="cn.titan6.spring.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>
    <bean id="userService" class="cn.titan6.spring.service.impl.UserServiceImpl"/>

这里采用的是mybatis-spring的MapperScannerConfigurer来实现将DAO对象置入IOC容器中，将会扫描并加入basePackage指定包下的所有DAO接口。

2. DAO接口与Service实现类

DAO简单的实现了一个查询所有信息的功能

package cn.titan6.spring.dao;

import cn.titan6.spring.bean.User;
import org.apache.ibatis.annotations.Select;

import java.util.List;


public interface UserDao {
    @Select("SELECT * FROM user")
    List<User> findAllUser();
}

UserService实现类采用Spring的注解方式自动通过构造器进行依赖注入UserDao

package cn.titan6.spring.service.impl;

import cn.titan6.spring.bean.User;
import cn.titan6.spring.dao.UserDao;
import cn.titan6.spring.service.UserService;
import org.springframework.stereotype.Component;

import java.util.List;

@Component("userService")
public class UserServiceImpl implements UserService {
    private final UserDao dao;

    public UserServiceImpl(UserDao dao) {
        this.dao = dao;
    }

    @Override
    public List<User> findAllUser() {
        return dao.findAllUser();
    }
}

3. 进行JUnit测试

import cn.titan6.spring.bean.User;
import cn.titan6.spring.config.SpringConfiguration;
import cn.titan6.spring.service.UserService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

public class SpringTest {
    @Test
    public void findAllUser() {
        ApplicationContext context = new ClassPathXmlApplicationContext("Application.xml");
        UserService userService = context.getBean("userService", UserService.class);
        List<User> allUser = userService.findAllUser();
        allUser.forEach(System.out::println);
    }
}