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如何使用spring配合mybatis配置多个数据源并应用？ （多DataSource）
使用多数据源的场景应该是很多的，如操作同一台服务器上不同的数据库，或者多地机器上的相同或不相同数据库。
虽然涉及到不同数据库时，我们也许可以通过跨库操作的方式，如 other.user 使用同一数据源来操作数据库，但是，这样明显使得应用很难扩展，单数据库将无法拆离。使用多数据源操作则可以解决这个问题。
在spring中怎样使用多数据源？本文通过实践方式，让我配置多数据源有个参考。（不得不说，java中很大的一个难点就在于配置环境）
从入口处更改，web.xml中添加引用spring配置文件：
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <display-name>c</display-name> <filter> <filter-name>characterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>dispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <!-- URL重写 --> <filter> <filter-name>UrlRewriteFilter</filter-name> <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class> </filter> <filter-mapping> <filter-name>UrlRewriteFilter</filter-name> <url-pattern>/*</url-pattern> <dispatcher>REQUEST</dispatcher> <dispatcher>FORWARD</dispatcher> </filter-mapping> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>/api/*</url-pattern> </servlet-mapping> <display-name>c</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> </welcome-file-list> <filter> <filter-name>JAMonFilter</filter-name> <filter-class>com.xx.core.web.filter.PageMonFilter</filter-class> <init-param> <param-name>flag</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>JAMonFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>exceptions</servlet-name> <jsp-file>/jamon/exceptions.jsp</jsp-file> </servlet> <servlet> </web-app>
2. 在application.xml中添加多数据源配置：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:mongo="http://www.springframework.org/schema/data/mongo" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/data/mongo http://www.springframework.org/schema/data/mongo/spring-mongo-1.5.xsd"> <bean class="com.xx.c.common.utils.SpringContextsUtil" /> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="${jdbc.url}" /> <property name="driverClassName" value="${jdbc.driver}" /> <property name="maxActive" value="${pool.maxPoolSize}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <!-- 超过时间限制是否回收 --> <property name="removeAbandoned" value="true" /> <!-- 超时时间；单位为秒。180秒=3分钟 --> <property name="removeAbandonedTimeout" value="${pool.removeAbandonedTimeout}" /> <!-- 配置获取连接等待超时的时间 --> <property name="maxWait" value="${pool.maxWait}" /> <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 --> <property name="timeBetweenEvictionRunsMillis" value="${pool.timeBetweenEvictionRunsMillis}" /> <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 --> <property name="minEvictableIdleTimeMillis" value="${pool.minEvictableIdleTimeMillis}" /> <property name="validationQuery" value="${pool.validationQuery} " /> <property name="testWhileIdle" value="true" /> <property name="testOnBorrow" value="false" /> <property name="testOnReturn" value="false" /> </bean> <bean id="dataSource_c" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="${jdbc2.url}" /> <property name="driverClassName" value="${jdbc2.driver}" /> <property name="maxActive" value="${pool2.maxPoolSize}" /> <property name="username" value="${jdbc2.username}" /> <property name="password" value="${jdbc2.password}" /> <property name="removeAbandoned" value="true" /> <property name="removeAbandonedTimeout" value="${pool2.removeAbandonedTimeout}" /> <property name="maxWait" value="${pool2.maxWait}" /> <property name="timeBetweenEvictionRunsMillis" value="${pool2.timeBetweenEvictionRunsMillis}" /> <property name="minEvictableIdleTimeMillis" value="${pool2.minEvictableIdleTimeMillis}" /> <property name="validationQuery" value="${pool2.validationQuery} " /> <property name="testWhileIdle" value="true" /> <property name="testOnBorrow" value="false" /> <property name="testOnReturn" value="false" /> </bean> <context:component-scan base-package="com.xx.c"> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" /> </context:component-scan> <context:component-scan base-package="com.xx.c.pojo.config" /> <bean class="com.xx.framework.web.v1_0_0.ServerController" /> <!-- spring的属性加载器，加载properties文件中的属性 --> <bean class="com.xx.zkc.property.PropertyPlaceholderConfigurer"> <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" /> <property name="ignoreResourceNotFound" value="true" /> <property name="locations"> <list> <value>classpath*:/spring/conf.properties</value> </list> </property> </bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:mybatis-config.xml" /> </bean> <bean id="sqlSessionFactory_c" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource_c" /> <property name="configLocation" value="classpath:mybatis-config.xml" /> </bean> <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate" scope="prototype"> <constructor-arg index="0" ref="sqlSessionFactory" /> </bean> <bean id="sqlSession_c" class="org.mybatis.spring.SqlSessionTemplate" scope="prototype"> <constructor-arg index="0" ref="sqlSessionFactory_c" /> </bean> <mongo:mongo id="mongo" replica-set="${mongodb.url}"> <mongo:options connections-per-host="${mongo.connections.per.host}" threads-allowed-to-block-for-connection-multiplier="${mongo.threads.allowed.to.block.for.connection.multiplier}" connect-timeout="${mongo.connect.timeout}" max-wait-time="${mongo.max.wait.time}" auto-connect-retry="${mongo.auto.connect.retry}" socket-keep-alive="${mongo.socket.keep.alive}" socket-timeout="${mongo.socket.timeout}" slave-ok="${mongo.slave.ok}" write-number="${mongo.write.number}" write-timeout="${mongo.write.timeout}" write-fsync="${mongo.write.fsync}" /> </mongo:mongo> <bean id="mappingContext" class="org.springframework.data.mongodb.core.mapping.MongoMappingContext" /> <bean id="defaultMongoTypeMapper" class="org.springframework.data.mongodb.core.convert.DefaultMongoTypeMapper"> <constructor-arg name="typeKey"> <null /> </constructor-arg> </bean> <bean id="mongoDbFactory" class="org.springframework.data.mongodb.core.SimpleMongoDbFactory"> <constructor-arg ref="mongo" /> <constructor-arg name="databaseName" value="${mongodb.databaseName}" /> </bean> <bean id="mappingMongoConverter" class="org.springframework.data.mongodb.core.convert.MappingMongoConverter"> <constructor-arg name="mappingContext" ref="mappingContext" /> <property name="typeMapper" ref="defaultMongoTypeMapper" /> <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" /> </bean> <bean id="mongodbReadPreference" class="com.mongodb.ReadPreference" factory-method="secondaryPreferred" /> <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate"> <property name="readPreference" ref="mongodbReadPreference" /> <constructor-arg name="mongoConverter" ref="mappingMongoConverter" /> <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" /> </bean> <!-- 事务 控制 begin --> <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <tx:annotation-driven transaction-manager="transactionManager" /> <!-- 事务 控制 end --> <!-- action begin --> <bean name='requestMappingHandlerMapping' class='com.xx.core.web.spring.annotation.PackageURLRequestMappingHandlerMapping'> <property name='packageBase' value='com.xx.c.action'></property> <property name="interceptors"> <list> <bean class="com.xx.core.web.spring.interceptor.SessionInterceptor"> <property name="on" value="${system.check.permission}" /> <property name="sessionTimeout" value="${system.timeout}" /> <property name="userSessionDao" ref="userSessionDao" /> <property name="systemDao" ref="systemDao" /> </bean> </list> </property> </bean> <!-- dao --> <import resource="dao.xml" /> <!-- service --> <import resource="service.xml" /> <!-- activemq --> <import resource="applicationContext-activemq.xml" /> <!-- redis --> <import resource="applicationContext-redis.xml" /> <!-- dubbo --> <import resource="applicationContext-dubbo.xml" /> <import resource="applicationContext-dubbo-consumer.xml" /> <import resource="classpath:spring/xx-c-kafka-consumer.xml" /> <import resource="applicationContext-rabbitmq-producer.xml"/> <import resource="applicationContext-rabbitmq-consumer.xml"/> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"> <property name="messageConverters"> <list> <bean class="com.xx.core.web.spring.convert.JSONHttpMessageConverter"> </bean> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> </bean> <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"> </bean> <bean class="org.springframework.http.converter.xml.SourceHttpMessageConverter"> </bean> <bean class="org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter"> </bean> </list> </property> <property name="customArgumentResolvers"> <list> <bean class="com.xx.core.web.spring.bind.TIDArgumentResolver" /> <bean class="com.xx.core.web.spring.bind.RequestAttributeArgumentResolver" /> <bean class="com.xx.core.web.spring.bind.ClientIPArgumentResolver" /> <bean class="com.xx.core.web.spring.bind.SessionUserIdArgumentResolver" /> </list> </property> </bean> <bean id="dealException" class="com.xx.core.web.spring.interceptor.ExceptionAop"></bean> <aop:config> <!-- 对异常的集中处理 --> <aop:aspect id="exceptionAop" ref="dealException"> <aop:pointcut id="exceptionPointCut" expression="execution(* com.xx.c.action.*.*.*(..))" /> <aop:around pointcut-ref="exceptionPointCut" method="deal" /> </aop:aspect> </aop:config> <bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator"> <property name="beanNames"> <list> <value>systemDictDao</value> <value>userDao</value> <value>infoDao</value> </list> </property> <property name="interceptorNames"> <list> <value>jamonInterceptor</value> </list> </property> </bean> <bean id="jamonInterceptor" class="org.springframework.aop.interceptor.JamonPerformanceMonitorInterceptor"></bean> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" p:defaultEncoding="utf-8" p:maxUploadSize="104857600" /> <context:component-scan base-package="com.xx.c.action" name-generator="com.xx.core.web.spring.annotation.FullPackageBeanNameGenerator" /> <!-- action end --> <!-- Spring托管线程池 --> <bean id="threadPoolTaskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor"> <!-- 线程池活跃的线程数 --> <property name="corePoolSize" value="50" /> <!-- 线程池最大活跃的线程数 --> <property name="maxPoolSize" value="75" /> <!-- 队列的最大容量 <property name ="queueCapacity" value ="2000" /> --> <!-- <property name="WaitForTasksToCompleteOnShutdown" value="true" /> --> </bean> <bean id="mapper" class="org.dozer.spring.DozerBeanMapperFactoryBean"> <property name="mappingFiles"> <list> <value>classpath:/dozerBeanMapping.xml</value> <value>classpath:/dozerBeanMapping2.xml</value> </list> </property> </bean> </beans>
3. 在dao.xml中，添加对数据源的引用：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" 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-4.0.xsd"> <!-- import this --> <bean id="userDao" class="com.xx.c.dao.user.UserDaoImpl"> <property name="sqlSession" ref="sqlSession" /> <property name="mongoTemplate" ref ="mongoTemplate" /> </bean> <bean id="infoDao" class="com.xx.c.dao.content.ConInfoDaoImpl"> <property name="sqlSession" ref="sqlSession_c" /> </bean> </beans>
4. 在具体的sql当中实现数据操作：
<?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.xx.c.dao.user.UserDao"> <resultMap id="userMap" type="User"> <id column="user_id" property="userId" /> <result column="username" property="userName" /> <result column="sex" property="sex" /> </resultMap> <resultMap id="userInfoMap" type="UserInfoBean"> <id column="user_id" property="userId" /> <result column="card_id" property="cardId" /> <result column="username" property="phone" /> <result column="id_card_address" property="idCardAddress" /> <result column="reg_time" property="regTime" /> <result column="logintime" property="logintime" /> <result column="last_time" property="lastTime" /> <result column="reg_ip" property="regIp" /> <result column="up_ip" property="upIp" /> <result column="last_ip" property="lastIp" /> <result column="download_channel" property="downloadChannel" /> <result column="guarantor1" property="guarantor1" /> <result column="guarantor_phone1" property="guarantor_phone1" /> </resultMap> <sql id="getUserCond"> <where> <if test="userId != null"> and u.user_id = #{userId} </if> <if test="userName != null and userName != ''"> and u.username = #{userName} </if> </where> </sql> <select id="getUser" resultMap="userMap" parameterType="User"> select u.* from users_info u <include refid="getUserCond" /> </select> <insert id="addDebitCardBindChannel" parameterType="DebitCardBindChannelBean"> insert into nzz ( user_id,channel, card_no,request_id,status) values ( #{userId},#{channel},#{cardNo},#{requestId},#{status}) </insert> <update id="updateDebitCardBindChannel" parameterType="DebitCardBindChannelBean"> update nzz set status=#{status} ,request_id=#{requestId} where user_id=#{userId} and card_no=#{cardNo} and channel=#{channel} </update> </mapper>
5. 完善一下，使用别名，使sql写的时候更简短：
<?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="logPrefix" value="dao."/> </settings> <!-- 配置别名，以便在引用时简写 --> <typeAliases> <typeAlias alias="User" type="com.xx.c.pojo.user.User" /> <typeAlias alias="CardBinBean" type="com.xx.c.pojo.user.CardBinBean"/> <typeAlias alias="UserCreditLogBean" type="com.xx.c.pojo.user.UserCreditLogBean"/> <typeAlias alias="InfoBean" type="com.xx.c.pojo.content.ContentInfo" /> </typeAliases> <mappers> <mapper resource="com/xx/c/dao/impl/User.xml"/> <mapper resource="com/xx/c/dao/impl/Info.xml"/> </mappers> </configuration>
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<bean id="readSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 实例化sqlSessionFactory时需要使用上述配置好的数据源以及SQL映射文件 --> <property name="dataSource" ref="readDataSource"/> <property name="mapperLocations" value="classpath:mapper/read/*.xml"/> </bean> <bean id="writeSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 实例化sqlSessionFactory时需要使用上述配置好的数据源以及SQL映射文件 --> <property name="dataSource" ref="writeDataSource"/> <property name="mapperLocations" value="classpath:mapper/write/*.xml"/> </bean>
通过MyBatis配置文件创建读写分离两个DataSource，每个SqlSessionFactoryBean对象的mapperLocations属性制定两个读写数据源的配置文件。将所有读的操作配置在读文件中，所有写的操作配置在写文件中
缺点：不够灵活、不易扩展
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