Spring+MyBatis多数据源配置实现

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%nlog4j.rootLogger=DEBUG,Consolelog4j.logger.com.cnblogs.lzrabbit=DEBUGlog4j.logger.org.springframework=ERRORlog4j.logger.org.mybatis=ERRORlog4j.logger.org.apache.ibatis=ERRORlog4j.logger.org.quartz=ERRORlog4j.logger.org.apache.axis2=ERRORlog4j.logger.org.apache.axiom=ERRORlog4j.logger.org.apache=ERRORlog4j.logger.httpclient=ERROR#log4j.additivity.org.springframework=false#Console log4j.appender.Console=org.apache.log4j.ConsoleAppenderlog4j.appender.Console.Threshold=DEBUG  log4j.appender.Console.Target=System.out  log4j.appender.Console.layout=org.apache.log4j.PatternLayout  log4j.appender.Console.layout.ConversionPattern=${ConversionPattern}#log4j.appender.Console.encoding=UTF-8#org.apache.log4j.DailyRollingFileAppenderlog4j.appender.DailyFile=org.apache.log4j.DailyRollingFileAppenderlog4j.appender.DailyFile.DatePattern='.'yyyy-MM-dd'.log'log4j.appender.DailyFile.File=${myApp.root}/logs/daily.loglog4j.appender.DailyFile.Append=truelog4j.appender.DailyFile.Threshold=DEBUGlog4j.appender.DailyFile.layout=org.apache.log4j.PatternLayoutlog4j.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.Driverjdbc.mysql.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=truejdbc.mysql.username=rootjdbc.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.Driverjdbc.sqlserver.url=jdbc:jtds:sqlserver://127.0.0.1:1433/testjdbc.sqlserver.username=sajdbc.sqlserver.password=sa#============================================================================# 通用配置#============================================================================jdbc.initialSize=5jdbc.minIdle=5jdbc.maxIdle=20jdbc.maxActive=100jdbc.maxWait=100000jdbc.defaultAutoCommit=falsejdbc.removeAbandoned=truejdbc.removeAbandonedTimeout=600jdbc.testWhileIdle=truejdbc.timeBetweenEvictionRunsMillis=60000jdbc.numTestsPerEvictionRun=20jdbc.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@Aspectpublic 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: 82014-05-25 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>