Spring+MyBatis多数据源配置实现示例

2024-03-01 20:10:03 160

最近用到了MyBatis配置多数据源，原以为简单配置下就行了，实际操作后发现还是要费些事的，这里记录下，以作备忘

不多废话，直接上代码，后面会有简单的实现介绍

jdbc和log4j的配置

#定义输出格式
ConversionPattern=%d%-5p[%t]%c-%m%n

log4j.rootLogger=DEBUG,Console
log4j.logger.com.cnblogs.lzrabbit=DEBUG
log4j.logger.org.springframework=ERROR
log4j.logger.org.mybatis=ERROR
log4j.logger.org.apache.ibatis=ERROR
log4j.logger.org.quartz=ERROR
log4j.logger.org.apache.axis2=ERROR
log4j.logger.org.apache.axiom=ERROR
log4j.logger.org.apache=ERROR
log4j.logger.httpclient=ERROR
#log4j.additivity.org.springframework=false
#Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.Threshold=DEBUG
log4j.appender.Console.Target=System.out
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=${ConversionPattern}
#log4j.appender.Console.encoding=UTF-8

#org.apache.log4j.DailyRollingFileAppender
log4j.appender.DailyFile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DailyFile.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.DailyFile.File=${myApp.root}/logs/daily.log
log4j.appender.DailyFile.Append=true
log4j.appender.DailyFile.Threshold=DEBUG
log4j.appender.DailyFile.layout=org.apache.log4j.PatternLayout
log4j.appender.DailyFile.layout.ConversionPattern=${ConversionPattern}
log4j.appender.DailyFile.encoding=UTF-8

#%c输出日志信息所属的类的全名
#%d输出日志时间点的日期或时间，默认格式为ISO8601，也可以在其后指定格式，比如：%d{yyy-MM-ddHH:mm:ss}，输出类似：2002-10-18-22：10：28
#%f输出日志信息所属的类的类名
#%l输出日志事件的发生位置，即输出日志信息的语句处于它所在的类的第几行
#%m输出代码中指定的信息，如log(message)中的message
#%n输出一个回车换行符，Windows平台为“rn”，Unix平台为“n”
#%p输出优先级，即DEBUG，INFO，WARN，ERROR，FATAL。如果是调用debug()输出的，则为DEBUG，依此类推
#%r输出自应用启动到输出该日志信息所耗费的毫秒数
#%t输出产生该日志事件的线程名

#============================================================================
#MySQL
#============================================================================
jdbc.mysql.driver=com.mysql.jdbc.Driver
jdbc.mysql.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
jdbc.mysql.username=root
jdbc.mysql.password=root

#============================================================================
#MSSQLServer
#============================================================================
#jdbc.sqlserver.driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
#jdbc.sqlserver.url=jdbc:sqlserver://127.0.0.1:1433;database=test;
#jdbc.sqlserver.username=sa
#jdbc.sqlserver.password=sa

#============================================================================
#MSSQLServer(JTDS)
#============================================================================
jdbc.sqlserver.driver=net.sourceforge.jtds.jdbc.Driver
jdbc.sqlserver.url=jdbc:jtds:sqlserver://127.0.0.1:1433/test
jdbc.sqlserver.username=sa
jdbc.sqlserver.password=sa


#============================================================================
#通用配置
#============================================================================
jdbc.initialSize=5
jdbc.minIdle=5
jdbc.maxIdle=20
jdbc.maxActive=100
jdbc.maxWait=100000
jdbc.defaultAutoCommit=false
jdbc.removeAbandoned=true
jdbc.removeAbandonedTimeout=600
jdbc.testWhileIdle=true
jdbc.timeBetweenEvictionRunsMillis=60000
jdbc.numTestsPerEvictionRun=20
jdbc.minEvictableIdleTimeMillis=300000

单数据源时的Spring配置文件

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<beanid="propertyConfigurer"class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<propertyname="location"value="classpath:jdbc.properties"/>
</bean>
<beanid="dataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close">
<propertyname="driverClassName"value="${jdbc.mysql.driver}"/>
<propertyname="url"value="${jdbc.mysql.url}"/>
<propertyname="username"value="${jdbc.mysql.username}"/>
<propertyname="password"value="${jdbc.mysql.password}"/>
<propertyname="initialSize"value="${jdbc.initialSize}"/>
<propertyname="minIdle"value="${jdbc.minIdle}"/>
<propertyname="maxIdle"value="${jdbc.maxIdle}"/>
<propertyname="maxActive"value="${jdbc.maxActive}"/>
<propertyname="maxWait"value="${jdbc.maxWait}"/>
<propertyname="defaultAutoCommit"value="${jdbc.defaultAutoCommit}"/>
<propertyname="removeAbandoned"value="${jdbc.removeAbandoned}"/>
<propertyname="removeAbandonedTimeout"value="${jdbc.removeAbandonedTimeout}"/>
<propertyname="testWhileIdle"value="${jdbc.testWhileIdle}"/>
<propertyname="timeBetweenEvictionRunsMillis"value="${jdbc.timeBetweenEvictionRunsMillis}"/>
<propertyname="numTestsPerEvictionRun"value="${jdbc.numTestsPerEvictionRun}"/>
<propertyname="minEvictableIdleTimeMillis"value="${jdbc.minEvictableIdleTimeMillis}"/>
</bean>
<beanid="sqlSessionFactory"class="org.mybatis.spring.SqlSessionFactoryBean">
<propertyname="dataSource"ref="dataSource"/>
</bean>

<!--mybatis.spring自动映射-->
<beanclass="org.mybatis.spring.mapper.MapperScannerConfigurer">
<propertyname="basePackage"value="com.cnblogs.lzrabbit"/>
</bean>

<!--自动扫描，多个包以逗号分隔-->
<context:component-scanbase-package="com.cnblogs.lzrabbit"/>
<aop:aspectj-autoproxy/>
</beans>

多数据源时Spring配置文件

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<beanid="propertyConfigurer"class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<propertyname="location"value="classpath:jdbc.properties"/>
</bean>
<beanid="sqlServerDataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close">
<propertyname="driverClassName"value="${jdbc.sqlserver.driver}"/>
<propertyname="url"value="${jdbc.sqlserver.url}"/>
<propertyname="username"value="${jdbc.sqlserver.username}"/>
<propertyname="password"value="${jdbc.sqlserver.password}"/>
<propertyname="initialSize"value="${jdbc.initialSize}"/>
<propertyname="minIdle"value="${jdbc.minIdle}"/>
<propertyname="maxIdle"value="${jdbc.maxIdle}"/>
<propertyname="maxActive"value="${jdbc.maxActive}"/>
<propertyname="maxWait"value="${jdbc.maxWait}"/>
<propertyname="defaultAutoCommit"value="${jdbc.defaultAutoCommit}"/>
<propertyname="removeAbandoned"value="${jdbc.removeAbandoned}"/>
<propertyname="removeAbandonedTimeout"value="${jdbc.removeAbandonedTimeout}"/>
<propertyname="testWhileIdle"value="${jdbc.testWhileIdle}"/>
<propertyname="timeBetweenEvictionRunsMillis"value="${jdbc.timeBetweenEvictionRunsMillis}"/>
<propertyname="numTestsPerEvictionRun"value="${jdbc.numTestsPerEvictionRun}"/>
<propertyname="minEvictableIdleTimeMillis"value="${jdbc.minEvictableIdleTimeMillis}"/>
</bean>
<beanid="mySqlDataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close">
<propertyname="driverClassName"value="${jdbc.mysql.driver}"/>
<propertyname="url"value="${jdbc.mysql.url}"/>
<propertyname="username"value="${jdbc.mysql.username}"/>
<propertyname="password"value="${jdbc.mysql.password}"/>
<propertyname="initialSize"value="${jdbc.initialSize}"/>
<propertyname="minIdle"value="${jdbc.minIdle}"/>
<propertyname="maxIdle"value="${jdbc.maxIdle}"/>
<propertyname="maxActive"value="${jdbc.maxActive}"/>
<propertyname="maxWait"value="${jdbc.maxWait}"/>
<propertyname="defaultAutoCommit"value="${jdbc.defaultAutoCommit}"/>
<propertyname="removeAbandoned"value="${jdbc.removeAbandoned}"/>
<propertyname="removeAbandonedTimeout"value="${jdbc.removeAbandonedTimeout}"/>
<propertyname="testWhileIdle"value="${jdbc.testWhileIdle}"/>
<propertyname="timeBetweenEvictionRunsMillis"value="${jdbc.timeBetweenEvictionRunsMillis}"/>
<propertyname="numTestsPerEvictionRun"value="${jdbc.numTestsPerEvictionRun}"/>
<propertyname="minEvictableIdleTimeMillis"value="${jdbc.minEvictableIdleTimeMillis}"/>
</bean>
<beanid="multipleDataSource"class="com.cnblogs.lzrabbit.MultipleDataSource">
<propertyname="defaultTargetDataSource"ref="mySqlDataSource"/>
<propertyname="targetDataSources">
<map>
<entrykey="mySqlDataSource"value-ref="mySqlDataSource"/>
<entrykey="sqlServerDataSource"value-ref="sqlServerDataSource"/>
</map>
</property>
</bean>
<beanid="sqlSessionFactory"class="org.mybatis.spring.SqlSessionFactoryBean">
<propertyname="dataSource"ref="multipleDataSource"/>
</bean>

<!--mybatis.spring自动映射-->
<beanclass="org.mybatis.spring.mapper.MapperScannerConfigurer">
<propertyname="basePackage"value="com.cnblogs.lzrabbit"/>
</bean>

<!--自动扫描，多个包以逗号分隔-->
<context:component-scanbase-package="com.cnblogs.lzrabbit"/>
<aop:aspectj-autoproxy/>
</beans>

MultipleDataSource实现

packagecom.cnblogs.lzrabbit;

importorg.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
*Createdbyrabbiton14-5-25.
*/
publicclassMultipleDataSourceextendsAbstractRoutingDataSource{
privatestaticfinalThreadLocal<String>dataSourceKey=newInheritableThreadLocal<String>();

publicstaticvoidsetDataSourceKey(StringdataSource){
dataSourceKey.set(dataSource);
}

@Override
protectedObjectdetermineCurrentLookupKey(){
returndataSourceKey.get();
}
}

MyBatis接口Mapper定义，直接使用注解方式实现

publicinterfaceMySqlMapper{
@Select("select*fromMyTable")
List<Map<String,Object>>getList();
}

publicinterfaceSqlServerMapper{
@Select("select*fromMyTable")
List<Map<String,Object>>getList();
}

手动数据源切换调用

packagecom.cnblogs.lzrabbit;

importorg.springframework.context.ApplicationContext;
importorg.springframework.context.support.ClassPathXmlApplicationContext;

/**
*Createdbyrabbiton14-5-25.
*/
publicclassMain{
publicstaticvoidmain(String[]args){
//初始化ApplicationContext
ApplicationContextapplicationContext=newClassPathXmlApplicationContext("applicationContext.xml");

MySqlMappermySqlMapper=applicationContext.getBean(MySqlMapper.class);

SqlServerMappersqlServerMapper=applicationContext.getBean(SqlServerMapper.class);

//设置数据源为MySql,使用了AOP测试时请将下面这行注释
MultipleDataSource.setDataSourceKey("mySqlDataSource");
mySqlMapper.getList();
//设置数据源为SqlServer,使用AOP测试时请将下面这行注释
MultipleDataSource.setDataSourceKey("sqlServerDataSource");
sqlServerMapper.getList();
}
}

使用SpringAOP方式实现自动切换

packagecom.cnblogs.lzrabbit;

importorg.aspectj.lang.ProceedingJoinPoint;
importorg.aspectj.lang.annotation.Around;
importorg.aspectj.lang.annotation.Aspect;
importorg.springframework.stereotype.Component;

@Component
@Aspect
publicclassMultipleDataSourceAspectAdvice{

@Around("execution(*com.cnblogs.lzrabbit.*.*(..))")
publicObjectdoAround(ProceedingJoinPointjp)throwsThrowable{
if(jp.getTarget()instanceofMySqlMapper){
MultipleDataSource.setDataSourceKey("mySqlDataSource");
}elseif(jp.getTarget()instanceofSqlServerMapper){
MultipleDataSource.setDataSourceKey("sqlServerDataSource");
}
returnjp.proceed();
}
}

调用日志

2014-05-2520:02:04,319DEBUG[main]com.jb51.lzrabbit.MySqlMapper.getList-oooUsingConnection[jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true,UserName=root@192.168.1.32,MySQLConnectorJava]
2014-05-2520:02:04,333DEBUG[main]com.jb51.lzrabbit.MySqlMapper.getList-==>Preparing:select*fromMyTable
2014-05-2520:02:04,371DEBUG[main]com.jb51.lzrabbit.MySqlMapper.getList-==>Parameters:
2014-05-2520:02:04,396DEBUG[main]com.jb51.lzrabbit.MySqlMapper.getList-<==Total:8
2014-05-2520:02:04,620DEBUG[main]com.jb51.lzrabbit.SqlServerMapper.getList-oooUsingConnection[jdbc:jtds:sqlserver://127.0.0.1:1433/test,UserName=sa,jTDSType4JDBCDriverforMSSQLServerandSybase]
2014-05-2520:02:04,620DEBUG[main]com.jb51.lzrabbit.SqlServerMapper.getList-==>Preparing:select*fromTmallCityMap
2014-05-2520:02:04,621DEBUG[main]com.jb51.lzrabbit.SqlServerMapper.getList-==>Parameters:
2014-05-2520:02:04,681DEBUG[main]com.jb51.lzrabbit.SqlServerMapper.getList-<==Total:397

这里就上面的实现做个简单解释，在我们配置单数据源时可以看到数据源类型使用了org.apache.commons.dbcp.BasicDataSource，而这个代码实现了javax.sql.DataSource接口

配置sqlSessionFactory时org.mybatis.spring.SqlSessionFactoryBean注入参数dataSource类型就是javax.sql.DataSource

实现多数据源的方法就是我们自定义了一个MultipleDataSource，这个类继承自AbstractRoutingDataSource，而AbstractRoutingDataSource继承自AbstractDataSource，AbstractDataSource实现了javax.sql.DataSource接口，所以我们的MultipleDataSource也实现了javax.sql.DataSource接口，可以赋值给sqlSessionFactory的dataSource属性

publicabstractclassAbstractRoutingDataSourceextendsAbstractDataSourceimplementsInitializingBean{}

publicabstractclassAbstractDataSourceimplementsDataSource{}

再来说下MultipleDataSource的实现原理，MultipleDataSource实现AbstractRoutingDataSource抽象类，然后实现了determineCurrentLookupKey方法，这个方法用于选择具体使用targetDataSources中的哪一个数据源

<beanid="multipleDataSource"class="com.cnblogs.lzrabbit.MultipleDataSource">
<propertyname="defaultTargetDataSource"ref="mySqlDataSource"/>
<propertyname="targetDataSources">
<map>
<entrykey="mySqlDataSource"value-ref="mySqlDataSource"/>
<entrykey="sqlServerDataSource"value-ref="sqlServerDataSource"/>
</map>
</property>
</bean>

可以看到Spring配置中multipleDataSource设置了两个属性defaultTargetDataSource和targetDataSources，这两个属性定义在AbstractRoutingDataSource，当MyBatis执行查询时会先选择数据源，选择顺序时现根据determineCurrentLookupKey方法返回的值到targetDataSources中去找，若能找到怎返回对应的数据源，若找不到返回默认的数据源defaultTargetDataSource，具体参考AbstractRoutingDataSource的源码

publicabstractclassAbstractRoutingDataSourceextendsAbstractDataSourceimplementsInitializingBean{

privateMap<Object,Object>targetDataSources;

privateObjectdefaultTargetDataSource;


/**
*RetrievethecurrenttargetDataSource.Determinesthe
*{@link#determineCurrentLookupKey()currentlookupkey},performs
*alookupinthe{@link#setTargetDataSourcestargetDataSources}map,
*fallsbacktothespecified
*{@link#setDefaultTargetDataSourcedefaulttargetDataSource}ifnecessary.
*@see#determineCurrentLookupKey()
*/
protectedDataSourcedetermineTargetDataSource(){
Assert.notNull(this.resolvedDataSources,"DataSourcerouternotinitialized");
ObjectlookupKey=determineCurrentLookupKey();
DataSourcedataSource=this.resolvedDataSources.get(lookupKey);
if(dataSource==null&&(this.lenientFallback||lookupKey==null)){
dataSource=this.resolvedDefaultDataSource;
}
if(dataSource==null){
thrownewIllegalStateException("CannotdeterminetargetDataSourceforlookupkey["+lookupKey+"]");
}
returndataSource;
}

/**
*Determinethecurrentlookupkey.Thiswilltypicallybe
*implementedtocheckathread-boundtransactioncontext.
*<p>Allowsforarbitrarykeys.Thereturnedkeyneeds
*tomatchthestoredlookupkeytype,asresolvedbythe
*{@link#resolveSpecifiedLookupKey}method.
*/
protectedabstractObjectdetermineCurrentLookupKey();

.............

}

在动态切换数据源方法时选择了AOP方式实现，这里实现的简单粗暴，具体应用时根据实际需要灵活变通吧

题外话，这里提下SqlServer驱动选择的问题，目前SqlServer的驱动主要有微软的官方驱动和JTDS驱动两种，关于这两个驱动我做过测试，批量更新，在小数据量(100以下)时，JTDS相对微软驱动性能稍微高一点点，在数据量增大时几万到上百万时，微软驱动有着明显优势，所以若对性能比较敏感，建议使用微软驱动，否则随意

微软驱动在Maven库找不到，这点比较郁闷，若使用maven的话还得先安装到本地，这点很不爽

JTDS使用比较方便Maven直接引用即可

Spring+MyBatis多数据源配置实现示例

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