一、准备工作
1.1准备jar包
建表语句:
CREATE TABLE `t_customer` ( `id` int(32) NOT NULL AUTO_INCREMENT, `username` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL, `jobs` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL, `phone` varchar(16) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL, PRIMARY KEY (`id`) USING BTREE ) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8;
1.2编写配置文件:
1.2.1db.properties
#dataSource #Thu Mar 07 16:27:40 CST 2019 jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/sm jdbc.username=root jdbc.password=123456 jdbc.maxTotal=30 jdbc.maxIdle=10 jdbc.initialSize=5
1.2.2 beans.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd" > <!-- 读取 db.properties--> <context:property-placeholder location = "classpath:db.properties"/> <!-- 配置数据源 --> <bean id = "dataSource" class = "org.apache.commons.dbcp2.BasicDataSource"> <!-- 数据库驱动 --> <property name = "driverClassName" value = "${jdbc.driver}" /> <!-- 数据库url --> <property name = "url" value = "${jdbc.url}" /> <!-- 数据库用户名 --> <property name = "username" value = "${jdbc.username}" /> <!-- 数据库密码 --> <property name = "password" value = "${jdbc.password}" /> <!-- 数据库最大连接数 --> <property name="maxTotal" value = "${jdbc.maxTotal}"/> <!-- 数据库最大空闲数 --> <property name="maxIdle" value = "${jdbc.maxIdle}"/> <!-- 初始化连接数 --> <property name="initialSize" value = "${jdbc.initialSize}"/> </bean> <!-- 配置事务管理,并指定数据源 --> <bean id = "transactionManager" class = "org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name = "dataSource" ref = "dataSource" /> </bean> <!-- 开启事务注解 --> <tx:annotation-driven transaction-manager = "transactionManager" /> <!-- 扫描注解 --> <context:component-scan base-package="com.sm.service"/> <!-- 配置MyBatis工厂 --> <bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据源 --> <property name="dataSource" ref = "dataSource"/> <!-- 指定核心配置文件 --> <property name="configLocation" value = "classpath:mybatis-config.xml"/> </bean> </beans>
1.2.3 mybatis-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> <!-- 采用扫描包定义别名 --> <typeAliases> <package name="com.sm.po"/> </typeAliases> <!-- 配置映射文件 --> <mappers> </mappers> </configuration>
二、基于Dao方式整合
2.1在src目录下创建com.sm.po包,并在包中创建Customer类
Customer.java
package com.sm.po; public class Customer { private Integer id; private String username; private String jobs; private String phone; public Customer() { // TODO Auto-generated constructor stub } public Customer(Integer id, String username, String jobs, String phone) { super(); this.id = id; this.username = username; this.jobs = jobs; this.phone = phone; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getJobs() { return jobs; } public void setJobs(String jobs) { this.jobs = jobs; } public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } @Override public String toString() { return "Customer [id=" + id + ", username=" + username + ", jobs=" + jobs + ", phone=" + phone + "]"; } }
2.2在com.sm.po包中创建CustomerMapper.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 = "com.sm.po.CustomerMapper" > <!-- 根据ID查询客户信息 --> <select id = "findCustomerById" parameterType = "Integer" resultType = "customer"> select * from t_customer where id = #{id} </select> </mapper>
2.3在mybatis-config.xml中添加映射文件(CustomerMapper.xml)
mybatis-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> <!-- 采用扫描包定义别名 --> <typeAliases> <package name="com.sm.po"/> </typeAliases> <!-- 配置映射文件 --> <mappers> <!-- 基于Dao --> <mapper resource = "com/sm/po/CustomerMapper.xml"/> </mappers> </configuration>
2.4创建一个com.sm.dao包,并在其中创建CustoemrDao接口
package com.sm.dao; import com.sm.po.Customer; public interface CustomerDao { public Customer findCustomerById(Integer id); }
2.5创建一个com.sm.dao.impl包,并在其中创建CustomerDao接口的实现类CustomerDaoImpl.
package com.sm.dao.impl; import org.mybatis.spring.support.SqlSessionDaoSupport; import com.sm.dao.CustomerDao; import com.sm.po.Customer; public class CustomerDaoImpl extends SqlSessionDaoSupport implements CustomerDao{ @Override public Customer findCustomerById(Integer id) { return this.getSqlSession().selectOne("com.sm.po.CustomerMapper.findCustomerById",id); } }
继承了SqlSessionDaoSupport,通过getSqlSession()获取sqlSession,并执行指定SQL语句。
获取SqlSession首先需要设置SqlSessionFactory,SqlSessionFactory通过spring注入。
SqlSessionDaoSupport :部分源码
Spring就是通过set方法将SqlSessionFactory注入,然后获取sqlSession。
2.6 在beans.xml中将SqlSessionFactory注入
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd" > <!-- 读取 db.properties--> <context:property-placeholder location = "classpath:db.properties"/> <!-- 配置数据源 --> <bean id = "dataSource" class = "org.apache.commons.dbcp2.BasicDataSource"> <!-- 数据库驱动 --> <property name = "driverClassName" value = "${jdbc.driver}" /> <!-- 数据库url --> <property name = "url" value = "${jdbc.url}" /> <!-- 数据库用户名 --> <property name = "username" value = "${jdbc.username}" /> <!-- 数据库密码 --> <property name = "password" value = "${jdbc.password}" /> <!-- 数据库最大连接数 --> <property name="maxTotal" value = "${jdbc.maxTotal}"/> <!-- 数据库最大空闲数 --> <property name="maxIdle" value = "${jdbc.maxIdle}"/> <!-- 初始化连接数 --> <property name="initialSize" value = "${jdbc.initialSize}"/> </bean> <!-- 配置事务管理,并指定数据源 --> <bean id = "transactionManager" class = "org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name = "dataSource" ref = "dataSource" /> </bean> <!-- 开启事务注解 --> <tx:annotation-driven transaction-manager = "transactionManager" /> <!-- 扫描注解 --> <context:component-scan base-package="com.sm.service"/> <!-- 配置MyBatis工厂 --> <bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据源 --> <property name="dataSource" ref = "dataSource"/> <!-- 指定核心配置文件 --> <property name="configLocation" value = "classpath:mybatis-config.xml"/> </bean> <!-- 实例化Bean dao,并将sqlSeesionFactory注入--> <bean id = "customerDao" class = "com.sm.dao.impl.CustomerDaoImpl"> <property name="sqlSessionFactory" ref = "sqlSessionFactory"></property> </bean> </beans>
2.7测试
package com.sm.test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.sm.dao.CustomerDao; import com.sm.dao.impl.CustomerDaoImpl; import com.sm.po.Customer; public class DaoTest { public static void main(String[] args) { ApplicationContext act = new ClassPathXmlApplicationContext("beans.xml"); CustomerDao cus = (CustomerDaoImpl)act.getBean("customerDao"); Customer custoemr = cus.findCustomerById(1); System.out.println(custoemr); } }
三、基于Mapper接口方式整合
采用基于Dao方式整合可以实现所需功能,但是也有一定的问题,例如执行语句的路径容易写错。
那么有什么方式可以将xxxxMapper.xml中语句的ID与Dao中的方法直接关联起来,这样调用方法时直接调用就可以了,
避免了自己编写语句路径出错。
基于Mapper接口方式整合就可以达到这种目的。
3.1在src目录下创建com.sm.mapper包,并在其中创建CustomerMapper.java和其映射文件CustomerMapper.xml。
CustomerMapper.java
package com.sm.mapper; import com.sm.po.Customer; public interface CustomerMapper { public Customer findCustomerById(Integer id); public void addCustomer(Customer customer); }
CustomerMapper.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.sm.mapper.CustomerMapper" > <!-- 根据ID查询客户信息 --> <select id = "findCustomerById" parameterType = "Integer" resultType = "customer"> select * from t_customer where id = #{id} </select> </mapper>
3.2在mybatis-config.xml中配置<mapper resource = "com/sm/mapper/CustomerMapper.xml"/>
3.3在beans.xml中将映射文件和接口关联起来
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd" > <!-- 读取 db.properties--> <context:property-placeholder location = "classpath:db.properties"/> <!-- 配置数据源 --> <bean id = "dataSource" class = "org.apache.commons.dbcp2.BasicDataSource"> <!-- 数据库驱动 --> <property name = "driverClassName" value = "${jdbc.driver}" /> <!-- 数据库url --> <property name = "url" value = "${jdbc.url}" /> <!-- 数据库用户名 --> <property name = "username" value = "${jdbc.username}" /> <!-- 数据库密码 --> <property name = "password" value = "${jdbc.password}" /> <!-- 数据库最大连接数 --> <property name="maxTotal" value = "${jdbc.maxTotal}"/> <!-- 数据库最大空闲数 --> <property name="maxIdle" value = "${jdbc.maxIdle}"/> <!-- 初始化连接数 --> <property name="initialSize" value = "${jdbc.initialSize}"/> </bean> <!-- 配置事务管理,并指定数据源 --> <bean id = "transactionManager" class = "org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name = "dataSource" ref = "dataSource" /> </bean> <!-- 开启事务注解 --> <tx:annotation-driven transaction-manager = "transactionManager" /> <!-- 扫描注解 --> <context:component-scan base-package="com.sm.service"/> <!-- 配置MyBatis工厂 --> <bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据源 --> <property name="dataSource" ref = "dataSource"/> <!-- 指定核心配置文件 --> <property name="configLocation" value = "classpath:mybatis-config.xml"/> </bean> <!-- 基于mapper --> <bean id = "customerMapper" class = "org.mybatis.spring.mapper.MapperFactoryBean"> <property name = "mapperInterface" value = "com.sm.mapper.CustomerMapper"/> <!--指定接口 --> <property name = "sqlSessionFactory" ref = "sqlSessionFactory" /> <!-- 指定sqlSessionFactory --> </bean> </beans>
测试:
package com.sm.test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.sm.mapper.CustomerMapper; import com.sm.po.Customer; public class MapperTest { public static void main(String[] args) { ApplicationContext act = new ClassPathXmlApplicationContext("beans.xml"); CustomerMapper customerMapper = act.getBean("customerMapper",CustomerMapper.class); Customer customer = customerMapper.findCustomerById(1); System.out.print(customer); } }
注:基于Mapper接口整合还需遵循以下规范:
Mapper接口的名称和对应的Mapper.xml文件的名称必须保持一致。
Mapper.xml文件中的namespace与Mapper接口的类路径要一致,即这两个文件是放在一个包中的。
Mapper接口中的方法和Mapper.xml中定义的sql语句的id要相同。
Mapper接口方法中的参数类型要与Mapper.xml中对应语句的类型(parameterType)相同。
Mapper接口方法的返回值与Mapper.xml中对应语句的返回值类型(resultType)要相同。
如果以上规范都遵循了,MyBatis就会自动生成Mapper接口实现类的代理对象,从而简化开发。
而且遵循了以上规范,可以不用再mybatis-config.xml中执行映射文件(<mapper resource = "xxx"/>)
三、基于MapperScannerConfigurer的整合
采用Mapper接口方式整合比基于Dao方式整合方便些,但是依然需要在配置文件(beans.xml)中编写大量配置。
那有没有更方便的方式呢,只需要指定接口和映射文件即可。
基于MapperSacnnerConfigurer就可以实现这一点。
我们将 基于Mapper接口实现整合中beans.xml中的关联部分删除。
beans.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd" > <!-- 读取 db.properties--> <context:property-placeholder location = "classpath:db.properties"/> <!-- 配置数据源 --> <bean id = "dataSource" class = "org.apache.commons.dbcp2.BasicDataSource"> <!-- 数据库驱动 --> <property name = "driverClassName" value = "${jdbc.driver}" /> <!-- 数据库url --> <property name = "url" value = "${jdbc.url}" /> <!-- 数据库用户名 --> <property name = "username" value = "${jdbc.username}" /> <!-- 数据库密码 --> <property name = "password" value = "${jdbc.password}" /> <!-- 数据库最大连接数 --> <property name="maxTotal" value = "${jdbc.maxTotal}"/> <!-- 数据库最大空闲数 --> <property name="maxIdle" value = "${jdbc.maxIdle}"/> <!-- 初始化连接数 --> <property name="initialSize" value = "${jdbc.initialSize}"/> </bean> <!-- 配置事务管理,并指定数据源 --> <bean id = "transactionManager" class = "org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name = "dataSource" ref = "dataSource" /> </bean> <!-- 开启事务注解 --> <tx:annotation-driven transaction-manager = "transactionManager" /> <!-- 扫描注解 --> <context:component-scan base-package="com.sm.service"/> <!-- 配置MyBatis工厂 --> <bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据源 --> <property name="dataSource" ref = "dataSource"/> <!-- 指定核心配置文件 --> <property name="configLocation" value = "classpath:mybatis-config.xml"/> </bean> <!-- 基于mapper 注释关联部分 --> <!-- <bean id = "customerMapper" class = "org.mybatis.spring.mapper.MapperFactoryBean"> <property name = "mapperInterface" value = "com.sm.mapper.CustomerMapper"/> <property name = "sqlSessionFactory" ref = "sqlSessionFactory" /> </bean> --> <!-- 基于MapperScannerConfigurer 指定basePackage,会自动扫描指定包,将包中映射文件和接口类关联 --> <bean class = "org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name = "basePackage" value = "com.sm.mapper"/> </bean> </beans>
采用自动扫描就可以省去繁琐的配置,使接口类和映射文件自动关联。
四、测试事务
4.1 将com.sm.mapper包中CustomerMapper.java和CustomerMapper.xml中加入添加方法。
CustomerMapper.java
package com.sm.mapper; import com.sm.po.Customer; public interface CustomerMapper { public Customer findCustomerById(Integer id); public void addCustomer(Customer customer); }
CustomerMapper.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.sm.mapper.CustomerMapper" > <!-- 根据ID查询客户信息 --> <select id = "findCustomerById" parameterType = "Integer" resultType = "customer"> select * from t_customer where id = #{id} </select> <!-- 添加用户 --> <insert id="addCustomer" parameterType = "customer"> insert into t_customer(username,jobs,phone) values(#{username}, #{jobs}, #{phone}) </insert> </mapper>
4.2创建com.sm.service包,并创建CustomerService接口
package com.sm.service; import com.sm.po.Customer; public interface CustomerService { public void addCustomer(Customer customer); }
4.3创建com.sm.serviceImpl包,并创建CustomerServiceImpl实现类
package com.sm.service.impl; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; import com.sm.mapper.CustomerMapper; import com.sm.po.Customer; import com.sm.service.CustomerService; @Service public class CustomerServiceImpl implements CustomerService{ @Autowired //按类型装配,使用注解自动注入 private CustomerMapper customerMapper; //@Transactional //事务 @Override public void addCustomer(Customer customer) { customerMapper.addCustomer(customer); int i = 1/0; } }
首先注释掉事务,如果没有事务addCustomer方法及时int i = 1/0报错,插入语句也会成功将数据插入。
如果有事务,int i = 1/0报错,插入也会失败。此处注释事务,比较注释前后区别。
4.4在beans.xml中采用自动扫描方式注册bean
beans.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd" > <!-- 读取 db.properties--> <context:property-placeholder location = "classpath:db.properties"/> <!-- 配置数据源 --> <bean id = "dataSource" class = "org.apache.commons.dbcp2.BasicDataSource"> <!-- 数据库驱动 --> <property name = "driverClassName" value = "${jdbc.driver}" /> <!-- 数据库url --> <property name = "url" value = "${jdbc.url}" /> <!-- 数据库用户名 --> <property name = "username" value = "${jdbc.username}" /> <!-- 数据库密码 --> <property name = "password" value = "${jdbc.password}" /> <!-- 数据库最大连接数 --> <property name="maxTotal" value = "${jdbc.maxTotal}"/> <!-- 数据库最大空闲数 --> <property name="maxIdle" value = "${jdbc.maxIdle}"/> <!-- 初始化连接数 --> <property name="initialSize" value = "${jdbc.initialSize}"/> </bean> <!-- 配置事务管理,并指定数据源 --> <bean id = "transactionManager" class = "org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name = "dataSource" ref = "dataSource" /> </bean> <!-- 开启事务注解 --> <tx:annotation-driven transaction-manager = "transactionManager" /> <!-- 扫描注解,扫描指定包,为其注册 --> <context:component-scan base-package="com.sm.service"/> <!-- 配置MyBatis工厂 --> <bean id = "sqlSessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据源 --> <property name="dataSource" ref = "dataSource"/> <!-- 指定核心配置文件 --> <property name="configLocation" value = "classpath:mybatis-config.xml"/> </bean> <!-- 基于MapperScannerConfigurer --> <bean class = "org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name = "basePackage" value = "com.sm.mapper"/> </bean> </beans>
测试:
package com.sm.test; import org.springframework.context.ApplicationContext; import com.my.util.MyBatisUtil; import com.sm.mapper.CustomerMapper; import com.sm.po.Customer; import com.sm.service.CustomerService; import com.sm.service.impl.CustomerServiceImpl; public class TransactionTest { public static void main(String[] args) { ApplicationContext act = MyBatisUtil.getApplicationContext("beans.xml"); CustomerService cs = act.getBean(CustomerService.class); cs.addCustomer(new Customer(10, "hhh", "stu", "177xxxx1234")); } }
没有注释事务注解,方法执行失败,但数据仍然会被插入表中。
我们将事务的注释去掉,再运行会发现方法执行失败,但数据不会被插入表中。
来源:https://www.cnblogs.com/huang-changfan/p/10492373.html