spring整合mybatis

先上官方文档http://mybatis.org/spring/zh/index.html
大致步骤如下：

1、导入依赖

这次要导入的依赖比较多（学到现在导的最多的一次，后面肯定更多。。）

		<dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>5.3.3version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-jdbcartifactId>
            <version>5.3.3version>
        dependency>
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>4.13.1version>
            <scope>testscope>
        dependency>
        <dependency>
            <groupId>org.aspectjgroupId>
            <artifactId>aspectjweaverartifactId>
            <version>1.9.6version>
        dependency>
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatis-springartifactId>
            <version>2.0.6version>
        dependency>
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.5.6version>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>5.1.47version>
        dependency>
        

2、配置dataSource

就是设置连接信息（注意看注释里有较详细介绍）

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    bean>

3、实现SqlSessionFactory与SqlSessionTemplate

在纯mybatis中都是new出来的，spring需要管理对象，所以这些工作要在spring里面做（注释里有较详细介绍）

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        
        <property name="mapperLocations" value="classpath:com/wt/dao/UserMapper.xml"/>
        
        <property name="configLocation" value="classpath:mybatis01-config.xml"/>
    bean>

    
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    bean>
    

4、写pojo、mapper这些

随便写一些用来测试（当然要看表写）
pojo:

package com.wt.pojo;

public class User {
     
    private int id;
    private String name;
    private String pwd;

    public User() {
     
    }

    public User(int id, String name, String pwd) {
     
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    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 getPwd() {
     
        return pwd;
    }

    public void setPwd(String pwd) {
     
        this.pwd = pwd;
    }
}

mapper：

package com.wt.dao;

import com.wt.pojo.User;

import java.util.List;

public interface UserMapper {
     

    List<User> getAllUsers();
}

mapper.xml：（mybatis的精华）

<mapper namespace="com.wt.dao.UserMapper">
    <select id="getAllUsers" resultType="User">
        select * from mybatis.user;
    select>
mapper>

mapperImpl：（相比纯mybtatis要多一个这个，在test的时候调用这个类里面的方法直接拿到结果，注释里有详细介绍）

package com.wt.dao;

import com.wt.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;

public class UserMapperImpl implements UserMapper{
     

    //这里相当于把之前学mybatis时的test内容那个拿到这里了，这里会被注入一个sqlSessionTemplate(也就是sqlSession换一种叫法)
    //然后获取mapper，执行mapper中的方法，再返回结果给调用方
    //多提一嘴，之前学mybatis时的test里面的创建SqlSessionFactory和SqlSession的实例都由spring来完成，这里的sqlSession也是在spring中被注入的
    private SqlSessionTemplate sqlSessionTemplate;

    public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
     
        this.sqlSessionTemplate = sqlSessionTemplate;
    }

    public List<User> getAllUsers(){
     
        UserMapper userMapper = sqlSessionTemplate.getMapper(UserMapper.class);
        return userMapper.getAllUsers();
    }
}

5、把写得mapperImpl在spring中"注册"

    <bean id="userMapper" class="com.wt.dao.UserMapperImpl">
        
        <property name="sqlSessionTemplate" ref="sqlSession"/>
    bean>

6、test

@Test
    public void testEv(){
     

//            try{
     
//                String resource = "mybatis01-config.xml";
//                InputStream inputStream = Resources.getResourceAsStream(resource);
//                SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//                SqlSession sqlSession = sqlSessionFactory.openSession();
//                UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
//                List users = userMapper.getAllUsers();
//                for(User user:users){
     
//                    System.out.println(user.getName());
//                }
//            } catch(IOException e) {
     
//                e.printStackTrace();
//            }
        //上面全部被取代了，只需要从spring中拿userMapper对象就行了
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        UserMapper userMapper = context.getBean("userMapper",UserMapper.class);
        List<User> users= userMapper.getAllUsers();
        for(User user:users){
     
            System.out.println(user.getName());
        }

    }

7、更便捷的方法

根据官方文档的介绍，不创建SqlSessionTemplate也可以，直接在用mapperImpl类继承一个类，然后再getSqlSession就ok了，详细：http://mybatis.org/spring/zh/sqlsession.html#SqlSessionDaoSupport
实现：
写mapperImpl类

package com.wt.dao;

import com.wt.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;

//这里就更简便了，SqlSessionTemplate的bean都不用创建了，直接继承SqlSessionDaoSupport然后通过getSqlSessionTemplate()方法获得
//sqlSessionTemplate，然后再在这个类的bean中注入SqlSessionFactory的bean就ok了
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{
     
    public List<User> getAllUsers(){
     
        SqlSessionTemplate sqlSessionTemplate = getSqlSessionTemplate();
        UserMapper userMapper = sqlSessionTemplate.getMapper(UserMapper.class);
        return userMapper.getAllUsers();
    }
}

托管给spring

<bean id="userMapper2" class="com.wt.dao.UserMapperImpl2">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    bean>

test

@Test
    public void test01(){
     
        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        UserMapper userMapper = context.getBean("userMapper2",UserMapper.class);
        List<User> users = userMapper.getAllUsers();
        for(User user:users){
     
            System.out.println(user.getName());
        }
    }

8、最后再贴一下mybatis核心配置文件
看看和纯mybatis相比有啥不同，当然mybatis核心配置文件可以被spring完全取代

<configuration>

    <typeAliases>
        <package name="com.wt.pojo">package>
    typeAliases>

    













    




configuration>