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-dd HH: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 #============================================================================ # MS SQL Server #============================================================================ #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 #============================================================================ # MS SQL Server (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
<?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" 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"> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:jdbc.properties"/> </bean> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.mysql.driver}"/> <property name="url" value="${jdbc.mysql.url}"/> <property name="username" value="${jdbc.mysql.username}"/> <property name="password" value="${jdbc.mysql.password}"/> <property name="initialSize" value="${jdbc.initialSize}"/> <property name="minIdle" value="${jdbc.minIdle}"/> <property name="maxIdle" value="${jdbc.maxIdle}"/> <property name="maxActive" value="${jdbc.maxActive}"/> <property name="maxWait" value="${jdbc.maxWait}"/> <property name="defaultAutoCommit" value="${jdbc.defaultAutoCommit}"/> <property name="removeAbandoned" value="${jdbc.removeAbandoned}"/> <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}"/> <property name="testWhileIdle" value="${jdbc.testWhileIdle}"/> <property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}"/> <property name="numTestsPerEvictionRun" value="${jdbc.numTestsPerEvictionRun}"/> <property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/> </bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> </bean> <!-- mybatis.spring自动映射 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.cnblogs.lzrabbit"/> </bean> <!-- 自动扫描，多个包以 逗号分隔 --> <context:component-scan base-package="com.cnblogs.lzrabbit"/> <aop:aspectj-autoproxy/> </beans>
多数据源时Spring配置文件
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:jdbc.properties"/> </bean> <bean id="sqlServerDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.sqlserver.driver}"/> <property name="url" value="${jdbc.sqlserver.url}"/> <property name="username" value="${jdbc.sqlserver.username}"/> <property name="password" value="${jdbc.sqlserver.password}"/> <property name="initialSize" value="${jdbc.initialSize}"/> <property name="minIdle" value="${jdbc.minIdle}"/> <property name="maxIdle" value="${jdbc.maxIdle}"/> <property name="maxActive" value="${jdbc.maxActive}"/> <property name="maxWait" value="${jdbc.maxWait}"/> <property name="defaultAutoCommit" value="${jdbc.defaultAutoCommit}"/> <property name="removeAbandoned" value="${jdbc.removeAbandoned}"/> <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}"/> <property name="testWhileIdle" value="${jdbc.testWhileIdle}"/> <property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}"/> <property name="numTestsPerEvictionRun" value="${jdbc.numTestsPerEvictionRun}"/> <property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/> </bean> <bean id="mySqlDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.mysql.driver}"/> <property name="url" value="${jdbc.mysql.url}"/> <property name="username" value="${jdbc.mysql.username}"/> <property name="password" value="${jdbc.mysql.password}"/> <property name="initialSize" value="${jdbc.initialSize}"/> <property name="minIdle" value="${jdbc.minIdle}"/> <property name="maxIdle" value="${jdbc.maxIdle}"/> <property name="maxActive" value="${jdbc.maxActive}"/> <property name="maxWait" value="${jdbc.maxWait}"/> <property name="defaultAutoCommit" value="${jdbc.defaultAutoCommit}"/> <property name="removeAbandoned" value="${jdbc.removeAbandoned}"/> <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}"/> <property name="testWhileIdle" value="${jdbc.testWhileIdle}"/> <property name="timeBetweenEvictionRunsMillis" value="${jdbc.timeBetweenEvictionRunsMillis}"/> <property name="numTestsPerEvictionRun" value="${jdbc.numTestsPerEvictionRun}"/> <property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/> </bean> <bean id="multipleDataSource" class="com.cnblogs.lzrabbit.MultipleDataSource"> <property name="defaultTargetDataSource" ref="mySqlDataSource"/> <property name="targetDataSources"> <map> <entry key="mySqlDataSource" value-ref="mySqlDataSource"/> <entry key="sqlServerDataSource" value-ref="sqlServerDataSource"/> </map> </property> </bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="multipleDataSource"/> </bean> <!-- mybatis.spring自动映射 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.cnblogs.lzrabbit"/> </bean> <!-- 自动扫描，多个包以 逗号分隔 --> <context:component-scan base-package="com.cnblogs.lzrabbit"/> <aop:aspectj-autoproxy/> </beans>
MultipleDataSource实现
package com.cnblogs.lzrabbit; import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource; /** * Created by rabbit on 14-5-25. */ public class MultipleDataSource extends AbstractRoutingDataSource { private static final ThreadLocal<String> dataSourceKey = new InheritableThreadLocal<String>(); public static void setDataSourceKey(String dataSource) { dataSourceKey.set(dataSource); } @Override protected Object determineCurrentLookupKey() { return dataSourceKey.get(); } }
MyBatis接口Mapper定义，直接使用注解方式实现
public interface MySqlMapper { @Select("select * from MyTable") List<Map<String,Object>> getList(); } public interface SqlServerMapper { @Select("select * from MyTable") List<Map<String,Object>> getList(); }
手动数据源切换调用
package com.cnblogs.lzrabbit; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * Created by rabbit on 14-5-25. */ public class Main { public static void main(String[] args) { //初始化ApplicationContext ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml"); MySqlMapper mySqlMapper = applicationContext.getBean(MySqlMapper.class); SqlServerMapper sqlServerMapper = 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
package com.cnblogs.lzrabbit; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.springframework.stereotype.Component; @Component @Aspect public class MultipleDataSourceAspectAdvice { @Around("execution(* com.cnblogs.lzrabbit.*.*(..))") public Object doAround(ProceedingJoinPoint jp) throws Throwable { if (jp.getTarget() instanceof MySqlMapper) { MultipleDataSource.setDataSourceKey("mySqlDataSource"); } else if (jp.getTarget() instanceof SqlServerMapper) { MultipleDataSource.setDataSourceKey("sqlServerDataSource"); } return jp.proceed(); } }
调用日志
2014-05-25 20:02:04,319 DEBUG [main] com.cnblogs.lzrabbit.MySqlMapper.getList - ooo Using Connection [jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true, UserName=root@192.168.1.32, MySQL Connector Java] 2014-05-25 20:02:04,333 DEBUG [main] com.cnblogs.lzrabbit.MySqlMapper.getList - ==> Preparing: select * from MyTable 2014-05-25 20:02:04,371 DEBUG [main] com.cnblogs.lzrabbit.MySqlMapper.getList - ==> Parameters: 2014-05-25 20:02:04,396 DEBUG [main] com.cnblogs.lzrabbit.MySqlMapper.getList - <== Total: 8 2014-05-25 20:02:04,620 DEBUG [main] com.cnblogs.lzrabbit.SqlServerMapper.getList - ooo Using Connection [jdbc:jtds:sqlserver://127.0.0.1:1433/test, UserName=sa, jTDS Type 4 JDBC Driver for MS SQL Server and Sybase] 2014-05-25 20:02:04,620 DEBUG [main] com.cnblogs.lzrabbit.SqlServerMapper.getList - ==> Preparing: select * from TmallCityMap 2014-05-25 20:02:04,621 DEBUG [main] com.cnblogs.lzrabbit.SqlServerMapper.getList - ==> Parameters: 2014-05-25 20:02:04,681 DEBUG [main] com.cnblogs.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
public abstract class AbstractRoutingDataSource extends AbstractDataSource implements InitializingBean { } public abstract class AbstractDataSource implements DataSource { }
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
<bean id="multipleDataSource" class="com.cnblogs.lzrabbit.MultipleDataSource"> <property name="defaultTargetDataSource" ref="mySqlDataSource"/> <property name="targetDataSources"> <map> <entry key="mySqlDataSource" value-ref="mySqlDataSource"/> <entry key="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
public abstract class AbstractRoutingDataSource extends AbstractDataSource implements InitializingBean { private Map<Object, Object> targetDataSources; private Object defaultTargetDataSource; /** * Retrieve the current target DataSource. Determines the * {@link #determineCurrentLookupKey() current lookup key}, performs * a lookup in the {@link #setTargetDataSources targetDataSources} map, * falls back to the specified * {@link #setDefaultTargetDataSource default target DataSource} if necessary. * @see #determineCurrentLookupKey() */ protected DataSource determineTargetDataSource() { Assert.notNull(this.resolvedDataSources, "DataSource router not initialized"); Object lookupKey = determineCurrentLookupKey(); DataSource dataSource = this.resolvedDataSources.get(lookupKey); if (dataSource == null && (this.lenientFallback || lookupKey == null)) { dataSource = this.resolvedDefaultDataSource; } if (dataSource == null) { throw new IllegalStateException("Cannot determine target DataSource for lookup key [" + lookupKey + "]"); } return dataSource; } /** * Determine the current lookup key. This will typically be * implemented to check a thread-bound transaction context. * <p>Allows for arbitrary keys. The returned key needs * to match the stored lookup key type, as resolved by the * {@link #resolveSpecifiedLookupKey} method. */ protected abstract Object determineCurrentLookupKey();
............. }
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
相关jar maven引用
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <org.springframework.version>3.2.7.RELEASE</org.springframework.version> </properties> <dependencies> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.7.2</version> </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version> </dependency> <dependency> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> <version>1.1.3</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${org.springframework.version}</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.4</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.2.2</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.6</version> </dependency> <dependency> <groupId>net.sourceforge.jtds</groupId> <artifactId>jtds</artifactId> <version>1.2.8</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.29</version> </dependency> </dependencies>