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Spring5入門-12-整合Mybatis

一、前言

環境:

  • mysql8.0.21
  • Spring 5.2.9
  • mybaits 3.5.5
  • mybatis-spring 2.0.5
  • aspectj 1.9.4
  • junit 4.12

要注意的事情:

在開始使用 MyBatis-Spring 之前,你需要先熟悉 Spring 和 MyBatis 這兩個框架和有關它們的術語。這很重要——因為本手冊中不會提供二者的基本內容,安裝和配置教程。

MyBatis-Spring 需要以下版本:

MyBatis-Spring MyBatis Spring 框架 Spring Batch Java
2.0 3.5+ 5.0+ 4.0+ Java 8+
1.3 3.4+ 3.2.2+ 2.1+ Java 6+


二、環境-回顧mybatis

2.1 依賴

<!--mysql8-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.21</version>
</dependency>

<!--Spring-->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.9.RELEASE</version>
</dependency>

<!--Mybatis-->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.5</version>
</dependency>

<!--Mybaits-Spring-->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.5</version>
</dependency>

<!--AOP織入-->
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.4</version>
</dependency>

<!--JUnit-->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>

2.2 資料庫


2.3 pojo

package com.duzhuan.pojo;

/**
 * @Autord: HuangDekai
 * @Date: 2020/10/11 15:35
 * @Version: 1.0
 * @since: jdk11
 */
public class User {
    private int id;
    private String name;
    private String 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;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }
}

2.4 mybatis配置檔案

路徑

程式碼

mybaits-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>

    <properties resource="db.properties"/>

    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>

    <typeAliases>
        <package name="com.duzhuan.pojo"/>
    </typeAliases>
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper class="com.duzhuan.mapper.UserMapper"/>
    </mappers>
</configuration>

這裡已經預先配好了mapper,請選擇合適自己路徑的mapper。

db.properties

driver = com.mysql.jdbc.Driver
url = jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=UTF8&serverTimezone=UTC
username = root
password = qq123456

2.5 mapper

路徑

注意事項

在此處的xml檔案等配置檔案,由於是Maven專案的原因,很有可能不能複製到target目錄下,即真正執行的路徑下沒有UserMapper.xml,因此需要在pom.xml的根標籤中加入以下配置:

<build>
    <resources>
        <resource>
            <directory>src/main/resource/</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
        <resource>
            <directory>src/main/java/</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
    </resources>
</build>

程式碼

UserMapper:

package com.duzhuan.mapper;

import com.duzhuan.pojo.User;

import java.util.List;

/**
 * @Autord: HuangDekai
 * @Date: 2020/10/11 20:06
 * @Version: 1.0
 * @since: jdk11
 */
public interface UserMapper {
    List<User> getUserList();
}

UserMapper.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.duzhuan.mapper.UserMapper">
    <select id="getUserList" resultType="User">
        select * from mybatis.user
    </select>
</mapper>

2.6 測試類

路徑

程式碼

UserMapperTest:

package com.duzhuan.mapper;

import com.duzhuan.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * @Autord: HuangDekai
 * @Date: 2020/10/11 20:16
 * @Version: 1.0
 * @since: jdk11
 */
public class UserMapperTest {
    @Test
    public void userMapperTest() throws IOException {
        String config = "mybatis-config.xml";

        InputStream inputStream = Resources.getResourceAsStream(config);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }

    }
}

結果



三、Mybatis-Spring SqlSessionTemplate

官方文件

基於以上環境,對其進行修改。

  1. 建立spring-dao.xml:

  2. 新增資料來源:

    <?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 https://www.springframework.org/schema/context/spring-context.xsd">
    
        <context:property-placeholder location="db.properties"/>
    
        <!--使用spring的資料來源替換Mybatis的配置
            這裡使用spring提供的JDBC-->
        <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=true&amp;useUnicode=true&amp;characterEncoding=UTF8&amp;serverTimezone=UTC"/>
            <property name="username" value="root"/>
            <property name="password" value="qq123456"/>
        </bean>
    
    </beans>
    

    這樣就可以刪掉mybatis-config.xml相關的部分:

     <properties resource="db.properties"/>
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    
  3. 設定mybatis配置和匯入mybatis配置。其實可以完全由Spring配置,但我習慣將<settings>typeAliases放在mybatis的配置檔案中,因此會用到匯入mybatis配置:

    <?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">
    
        <context:property-placeholder location="db.properties"/>
    
        <!--使用spring的資料來源替換Mybatis的配置
            這裡使用spring提供的JDBC-->
        <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=true&amp;useUnicode=true&amp;characterEncoding=UTF8&amp;serverTimezone=UTC"/>
            <property name="username" value="root"/>
            <property name="password" value="qq123456"/>
        </bean>
    
        <!--sqlSessionFactory-->
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            <property name="dataSource" ref="dataSource"/>
    
            <!--
            匯入mybatis的配置
            其實可以純spring配置mybatis,無需匯入。
            -->
            <property name="configLocation" value="mybatis-config.xml"/>
            <!--比如這個,繫結UserMapper-->
            <property name="mapperLocations" value="classpath:com/duzhuan/mapper/UserMapper.xml"/>
        </bean>
    
    </beans>
    

    由於有<property name="mapperLocations" value="classpath:com/duzhuan/mapper/UserMapper.xml"/>,因此可以刪掉mybatis-config.xml中的:

    <mappers>
        <mapper class="com.duzhuan.mapper.UserMapper"/>
    </mappers>
    
  4. 配置sqlSession:

    1. spring-mybatis中,是沒有sqlSession的,sqlSessionTemplate等價於sqlSession。開啟org.mybatis.spring.SqlSessionTemplate可以看到的是:

      它沒有Setter方法,只能構造器注入。

    2. spring-dao.xml中新增:

      <!--sqlSession-->
      <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
          <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/>
      </bean>
      
  5. 有了sqlSession,下一步就應該getMapper了。

    建立UserMapperImpl:

    程式碼:

    package com.duzhuan.mapper;
    
    import com.duzhuan.pojo.User;
    import org.mybatis.spring.SqlSessionTemplate;
    
    import java.util.List;
    
    /**
     * @Autord: HuangDekai
     * @Date: 2020/10/12 15:29
     * @Version: 1.0
     * @since: jdk11
     */
    public class UserMapperImpl implements UserMapper{
    
        private SqlSessionTemplate sqlSessionTemplate;
    
        public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
            this.sqlSessionTemplate = sqlSessionTemplate;
        }
    
        @Override
        public List<User> getUserList() {
            UserMapper userMapper = sqlSessionTemplate.getMapper(UserMapper.class);
            return userMapper.getUserList();
        }
    }
    

    spring-dao.xml中新增:

    <!--Mapper-->
    <bean id="userMapper" class="com.duzhuan.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>
    
  6. 修改UserMapperTest:

    package com.duzhuan.mapper;
    
    import com.duzhuan.pojo.User;
    
    import org.junit.Test;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import java.io.IOException;
    import java.util.List;
    
    /**
     * @Autord: HuangDekai
     * @Date: 2020/10/11 20:16
     * @Version: 1.0
     * @since: jdk11
     */
    public class UserMapperTest {
        @Test
        public void userMapperTest() throws IOException {
            ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
            UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
            List<User> userList = userMapper.getUserList();
            for (User user : userList) {
                System.out.println(user);
            }
        }
    }
    

執行測試樣例結果:

附上spring-dao.xml全程式碼:

<?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">

    <context:property-placeholder location="db.properties"/>

    <!--使用spring的資料來源替換Mybatis的配置
        這裡使用spring提供的JDBC-->
    <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=true&amp;useUnicode=true&amp;characterEncoding=UTF8&amp;serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="qq123456"/>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>

        <!--
        匯入mybatis的配置
        其實可以純spring配置mybatis,無需匯入。
        -->
        <property name="configLocation" value="mybatis-config.xml"/>
        <!--比如這個,繫結UserMapper-->
        <property name="mapperLocations" value="classpath:com/duzhuan/mapper/UserMapper.xml"/>
    </bean>

    <!--sqlSession-->
    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>

    <!--Mapper-->
    <bean id="userMapper" class="com.duzhuan.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>
</beans>


四、SqlSessionDaoSupport

官方文件-SqlSessionDaoSupport

另外一種方法。

建立一個UserMapper的實現類UserMapperDaoSupport

程式碼:

package com.duzhuan.mapper;

import com.duzhuan.pojo.User;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;

/**
 * @Autord: HuangDekai
 * @Date: 2020/10/12 17:25
 * @Version: 1.0
 * @since: jdk11
 */
public class UserMapperDaoSupportImpl extends SqlSessionDaoSupport implements UserMapper {

    @Override
    public List<User> getUserList() {
        return getSqlSession().getMapper(UserMapper.class).getUserList();
    }
}

spring-dao.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: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">

    <context:property-placeholder location="db.properties"/>

    <!--使用spring的資料來源替換Mybatis的配置
        這裡使用spring提供的JDBC-->
    <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=true&amp;useUnicode=true&amp;characterEncoding=UTF8&amp;serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="qq123456"/>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>

        <!--
        匯入mybatis的配置
        其實可以純spring配置mybatis,無需匯入。
        -->
        <property name="configLocation" value="mybatis-config.xml"/>
        <!--比如這個,繫結UserMapper-->
        <property name="mapperLocations" value="classpath:com/duzhuan/mapper/UserMapper.xml"/>
    </bean>

    <!--sqlSession-->
    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>

    <!--Mapper-->
    <bean id="userMapper" class="com.duzhuan.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>

<!--====================add===============-->
    <bean id="UserMapperDaoSupportImpl" class="com.duzhuan.mapper.UserMapperDaoSupportImpl">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
<!--====================add===============-->
</beans>

執行結果: