SSM配置多數據源
一直以來用的都是mysql數據庫，後來有將mysql數據庫切換爲sqlite，現在這個項目需要同時配置這兩個數據源，基於別人的基礎整理一個配置多數源的框架。僅供參考
導包
如果同時想用mysql 和sqlite，首先導入連接這兩個數據庫需要的jar包
mysql驅動包
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
</dependency>
sqlite驅動包
<dependency>
<groupId>org.xerial</groupId>
<artifactId>sqlite-jdbc</artifactId>
<version>3.7.2</version>
</dependency>
配置spring-mybatis.xml
這是配置單個數據源的
<?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:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:cache="http://www.springframework.org/schema/cache"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
http://www.springframework.org/schema/cache
http://www.springframework.org/schema/cache/spring-cache.xsd">
<!-- 加載數據庫配置文件 -->
<context:property-placeholder location="classpath:db/Mysql.properties" />
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName">
<value>${driverClassName}</value>
</property>
<property name="url">
<value>${url}</value>
</property>
<property name="username">
<value>${dbUserName}</value>
</property>
<property name="password">
<value>${dbPassword}</value>
</property>
<property name="testWhileIdle" value="true" />
<property name="testOnBorrow" value="true" />
<property name="testOnReturn" value="true" />
<property name="validationQuery" value="SELECT 1 FROM DUAL" />
</bean>
<!-- 配置SqlSessionFctory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="mapperLocations" value="classpath:mapper/*.Mapper.xml" />
<property name="dataSource" ref="dataSource" />
<property name="plugins">
<bean class="com.sys.common.PaginationInterceptor" />
</property>
</bean>
<!-- SqlSessionTemplate 是 MyBatis-Spring 的核心 -->
<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="0" ref="sqlSessionFactory" />
</bean>
<!-- Spring事務控制（txManager） -->
<bean id="txManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<!-- enable transaction annotation support -->
<tx:annotation-driven transaction-manager="txManager" />
</beans>
配置多個數據源
<?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:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:cache="http://www.springframework.org/schema/cache"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
http://www.springframework.org/schema/cache
http://www.springframework.org/schema/cache/spring-cache.xsd">
<!-- 加載數據庫配置文件 -->
<context:property-placeholder location="classpath:db/Mysql.properties" />
<bean id="dataSourceMysql" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName">
<value>${driverClassName}</value>
</property>
<property name="url">
<value>${url}</value>
</property>
<property name="username">
<value>${dbUserName}</value>
</property>
<property name="password">
<value>${dbPassword}</value>
</property>
</bean>
<!--數據庫sqlite連接池 -->
<bean id="dataSourceSqlite" class="org.apache.commons.dbcp.BasicDataSource">
<!-- 指定連接數據庫的驅動 -->
<property name="driverClassName" value="org.sqlite.JDBC" />
<!-- 指定連接數據庫的URL sqlite使用絕對路徑 -->
<property name="url" value="jdbc:sqlite:E:/sqlite/kanban.db" />
</bean>
<bean id="dataSource" class="com.sys.dynamic.database.DynamicDataSource">
<!--默認數據源 -->
<property name="defaultTargetDataSource" ref="dataSourceSqlite" />
<property name="targetDataSources">
<map key-type="java.lang.String">
<!--這裏是上面數據源配置的bean id -->
<entry key="dataSourceMysql" value-ref="dataSourceMysql" />
<entry key="dataSourceSqlite" value-ref="dataSourceSqlite" />
</map>
</property>
</bean>
<!-- 配置SqlSessionFctory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="mapperLocations" value="classpath:mapper/*.xml" />
<property name="dataSource" ref="dataSource" />
<property name="plugins">
<bean class="com.sys.common.PaginationInterceptor" />
</property>
</bean>
<!-- SqlSessionTemplate 是 MyBatis-Spring 的核心 -->
<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="0" ref="sqlSessionFactory" />
</bean>
<!-- Spring事務控制（txManager） -->
<bean id="txManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<!-- enable transaction annotation support -->
<tx:annotation-driven transaction-manager="txManager" />
<!-- 配置mybatis mapper接口 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.sys.dao" />
<property name="sqlSessionTemplateBeanName" value="sqlSessionTemplate" />
</bean>
</beans>
配置 spring-context.xml
增加切面注入的配置
<!--基於aspectj註解的配置文件在spring中的配置-->
<aop:aspectj-autoproxy expose-proxy="true"/>
<!--對這裏加以改動，直接在類中進行配置-->
<!--設置切面進行攔截-->
<aop:config>
<!--設置事務的優先級-->
<aop:aspect ref="dataSwitchAop" order="0">
<!--攔截所有的service的方法-->
<!--當然也可以攔截Controller方法，這裏設置的是攔截service-->
<aop:pointcut id="dataSourcePointcut" expression="execution(* com.sys.service.*Service..*(..))"/>
<aop:before method="intercept" pointcut-ref="dataSourcePointcut"/>
<aop:after method="clearDataSource" pointcut-ref="dataSourcePointcut"/>
</aop:aspect>
</aop:config>
<!--如果要設置攔截controller方法的話需要將參數設置爲true，啓動cligb代理-->
<aop:aspectj-autoproxy proxy-target-class="true"/>
配置多個數據源的原理
利用spring的切面注入，在service層或者controller層進行攔截切換數據源
package com.sys.dynamic.database;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
@Documented
public @interface DataSource {
String value() default "";
}
package com.sys.dynamic.database;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
//第一個類，我自定義的類，這個類還需要注入到spring中進行配置
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DynamicDataSourceHolder.getDataSource();
}
}
package com.sys.dynamic.database;
public class DynamicDataSourceHolder {
//private static final ThreadLocal<String> dataSourceKey = new InheritableThreadLocal<String>();
private static final ThreadLocal<String> dataSourceKey = new ThreadLocal<String>();
public static String getDataSource() {
return dataSourceKey.get();
}
public static void setDataSource(String dataSource) {
dataSourceKey.set(dataSource);
}
public static void clearDataSource() {
dataSourceKey.remove();
}
}
package com.sys.dynamic.database;
import java.lang.reflect.Method;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;
@Component
public class DataSwitchAop {
/**
* 攔截目標方法，獲取由@DataSource指定的數據源標識，設置到線程存儲中以便切換數據源
*
* @param point
* @throws Exception
*/
public void intercept(JoinPoint point) throws Exception {
System.out.println("==========切換數據源=================");
Class<?> target = point.getTarget().getClass();
MethodSignature signature = (MethodSignature) point.getSignature();
// 默認使用目標類型的註解，如果沒有則使用其實現接口的註解
for (Class<?> clazz : target.getInterfaces()) {
resolveDataSource(clazz, signature.getMethod());
}
resolveDataSource(target, signature.getMethod());
}
/**
* 提取目標對象方法註解和類型註解中的數據源標識
*
* @param clazz
* @param method
*/
private void resolveDataSource(Class<?> clazz, Method method) {
try {
Class<?>[] types = method.getParameterTypes();
// 默認使用類型註解
if (clazz.isAnnotationPresent(DataSource.class)) {
DataSource source = clazz.getAnnotation(DataSource.class);
DynamicDataSourceHolder.setDataSource(source.value());
}
// 方法註解可以覆蓋類型註解
Method m = clazz.getMethod(method.getName(), types);
if (m != null && m.isAnnotationPresent(DataSource.class)) {
DataSource source = m.getAnnotation(DataSource.class);
DynamicDataSourceHolder.setDataSource(source.value());
}
} catch (Exception e) {
System.out.println(clazz + ":" + e.getMessage());
}
}
/**
* @param
* @return void 方法調用完畢後，清除緩存的數據源，不然在多線程的切換中會報錯，導致另一個數據源的數據使用了前一個數據源的數據
*/
@SuppressWarnings("unused")
private void clearDataSource() {
System.out.println("=================清除緩存==============");
DynamicDataSourceHolder.clearDataSource();
}
}
使用
在service層增加註解來切換數據源，spring-content.xml中有配置 所掃描的包要和配置中的一致
