Java--Spring和MyBatis集成

╰+哭是因爲堅強的太久メ 2023-10-01 19:54 12阅读 0赞

Spring集成Mybatis主要使用的spring的IOC技术

创建项目步骤：

1、新建普通的maven项目

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBATWluZ2dlUWluZ2NodW4_size_6_color_FFFFFF_t_70_g_se_x_16][]

2、加入maven的依赖

（1）spring依赖

（2）mybatis依赖

（3）mysql驱动

（4）spring的事务依赖

（5）mybatis和spring集成依赖

<dependencies>
    
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.11</version>
                <scope>test</scope>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>5.2.5.RELEASE</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-tx</artifactId>
                <version>5.2.5.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-jdbc</artifactId>
                <version>5.2.5.RELEASE</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.5.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
                <version>2.0.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.9</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>1.2.6</version>
            </dependency>
    
        </dependencies>

3、创建实体类（使用mysql数据库建一张User用户表）

4、创建dao接口和mapper文件

UserDao.java

public interface UserDao {
        /**
         * 插入一条user记录
         * @param user
         * @return
         */
        int insertUser(User user);
    
        /**
         * 查询所有用户
         * @param user
         * @return
         */
        List<User> selectUsers(User user);
    }

UserDao.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.mycompany.dao.UserDao">
    
        <insert id="insertUser">
            insert into user values(#{userId},#{userName},#{email},#{age})
        </insert>
    
        <select id="selectUsers" resultType="User">
            select user_id,user_name,email,age
            from user
            order by user_id desc
      </select>
    </mapper>

5、创建mybatis主配置文件 mybatis-config.xml

（1）主配置文件中不再需要数据源的配置了；数据源要交给 Spring 容器管理

（2） mapper 映射文件的注册，使用<package/>标签，即只需给出 mapper 映射文件所在的包即可

<?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"/>
        </settings>
    
        
        <typeAliases>
            
    
    
            
            <package name="com.mycompany.domain" />
        </typeAliases>
    
    
        
        
    
    
        
        <mappers>
            
    
    
            
            <package name="com.mycompany.dao" />
    
        </mappers>
    
    </configuration>

6、创建service接口和实现类，属性是dao

public interface UserService {
        //插入一条user记录
        int insertUser(User user);
    
        //查询所有用户
        List<User> selectUsers(User user);
    }
    
    
    public class UserServiceImpl implements UserService {
    
        private UserDao userDao;
    
        public void setUserDao(UserDao userDao) {
            this.userDao = userDao;
        }
    
        @Override
        public int insertUser(User user) {
            int nums = userDao.insertUser(user);
            return nums;
        }
    
        @Override
        public List<User> selectUsers(User user) {
            List<User> userList = userDao.selectUsers(user);
            return userList;
        }
    }

7、创建spring的配置文件：声明mybatis对象交给spring创建

（1）数据源DataSource

这里使用阿里的Druid数据库连接池

Druid官网：[https://github.com/alibaba/druid][https_github.com_alibaba_druid]

DruidDataSource配置：

[https://github.com/alibaba/druid/wiki/DruidDataSource%E9%85%8D%E7%BD%AE][https_github.com_alibaba_druid_wiki_DruidDataSource_E9_85_8D_E7_BD_AE]

其中Druid通用配置示例：

在上面的配置中，通常你需要配置url、username、password，maxActive这三项。

Druid会自动跟url识别驱动类名，如果连接的数据库非常见数据库，配置属性driverClassName

<context:property-placeholder location="classpath:jdbc.properties" />
    
        
        <bean id="myDataSource" class="com.alibaba.druid.pool.DruidDataSource"
                init-method="init" destroy-method="close">
            
            
            <property name="url" value="${jdbc.url}" />
            <property name="username" value="${jdbc.user}" />
            <property name="password" value="${jdbc.password}" />
            <property name="maxActive" value="${jdbc.maxActive}" />
        </bean>

（2）SqlSessionFactory

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" >
            
            <property name="dataSource" ref="myDataSource" />
    
            
            <property name="configLocation" value="classpath:mybatis-config.xml" />
        </bean>

（3）Dao对象

Mapper 扫描配置器 MapperScannerConfigurer 会自动生成指定的基本包中 mapper 的代理对象。该 Bean 无需设置 id 属性。basePackage 使用分号或逗号设置多个包

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
            
            <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    
            
            <property name="basePackage" value="com.mycompany.dao" />
        </bean>

（4）声明自定义的service

<bean id="userService" class="com.mycompany.service.impl.UserServiceImpl">
            
            <property name="userDao" ref="userDao" />
        </bean>

jdbc.properties；数据库属性配置文件

jdbc.driver=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/ssm
    jdbc.user=root
    jdbc.password=123456
    jdbc.maxActive=20

applicationContext.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="classpath:jdbc.properties" />
    
        
        <bean id="myDataSource" class="com.alibaba.druid.pool.DruidDataSource"
                init-method="init" destroy-method="close">
            
            
            <property name="url" value="${jdbc.url}" />
            <property name="username" value="${jdbc.user}" />
            <property name="password" value="${jdbc.password}" />
            <property name="maxActive" value="${jdbc.maxActive}" />
        </bean>
    
        
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" >
            
            <property name="dataSource" ref="myDataSource" />
    
            
            <property name="configLocation" value="classpath:mybatis-config.xml" />
        </bean>
    
        
        <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
            
            <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    
            
            <property name="basePackage" value="com.mycompany.dao" />
        </bean>
    
        
        <bean id="userService" class="com.mycompany.service.impl.UserServiceImpl">
            
            <property name="userDao" ref="userDao" />
        </bean>
    
    </beans>

8、创建测试类

public class TestSpringMybatis {
        @Test
        public void testSpringMybatis(){
            String config = "applicationContext.xml";
            ApplicationContext ac = new ClassPathXmlApplicationContext(config);
    
            //获取容器中所有对象名
            String names[] = ac.getBeanDefinitionNames();
            for (String name:names){
                System.out.println("容器中对象名称：" + name + "    " + ac.getBean(name));
            }
        }
    
        @Test
        public void testDaoInsertUser(){
            String config = "applicationContext.xml";
            ApplicationContext ac = new ClassPathXmlApplicationContext(config);
    
            //获取容器中的Dao对象
            UserDao userDao = (UserDao) ac.getBean("userDao");
    
            User user = new User();
            user.setUserName("admin11");
            user.setEmail("admin@123.com");
            user.setAge(16);
    
            //spring和mybatis整合在一起使用，事务是自动提交的。 无需执行SqlSession.commit();
            int nums = userDao.insertUser(user);
            System.out.println("nums=" + nums);
        }
    
    
        @Test
        public void testServiceInsertUser(){
            String config = "applicationContext.xml";
            ApplicationContext ac = new ClassPathXmlApplicationContext(config);
    
            //获取容器中的Dao对象
            UserService userService = (UserService) ac.getBean("userService");
    
            User user = new User();
            user.setUserName("admin22");
            user.setEmail("admin21332@123.com");
            user.setAge(28);
            int nums = userService.insertUser(user);
            System.out.println("nums=" + nums);
        }
    
        @Test
        public void testSelect(){
            String config = "applicationContext.xml";
            ApplicationContext ac = new ClassPathXmlApplicationContext(config);
    
            //获取容器中的Dao对象
            UserService userService = (UserService) ac.getBean("userService");
    
            List<User> userList = userService.selectUsers(null);
            for (User user:userList){
                System.out.println("user:" + user);
            }
        }
    }

容器中输出对象

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBATWluZ2dlUWluZ2NodW4_size_20_color_FFFFFF_t_70_g_se_x_16][]

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[https_github.com_alibaba_druid]: https://github.com/alibaba/druid
[https_github.com_alibaba_druid_wiki_DruidDataSource_E9_85_8D_E7_BD_AE]: https://github.com/alibaba/druid/wiki/DruidDataSource%E9%85%8D%E7%BD%AE
[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBATWluZ2dlUWluZ2NodW4_size_20_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/39d5d0aec6ed42478ee05e875c83a48d.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBATWluZ2dlUWluZ2NodW4=,size_20,color_FFFFFF,t_70,g_se,x_16