Spring+MyBatis多数据源配置实现

>>强大,10k+点赞的 SpringBoot 后台管理系统竟然出了详细教程!

点击上方“Java知音”,选择“置顶公众号”

技术文章第一时间送达!


作者:懒惰的肥兔

链接:https://www.cnblogs.com/lzrabbit

公众号注:Spring技术专栏,点击文末阅读原文直达


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

log4j.properties


#============================================================================
# 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

jdbc.properties


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>

applicationContext.xml


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>

applicationContext.xml


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>


看完本文有收获?请转发分享给更多人

Spring+MyBatis多数据源配置实现


Spring+MyBatis多数据源配置实现

戳下面的原文阅读,更有料