项目结构:

配置文件：applicationContext.xml

<?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:aop="http://www.springframework.org/schema/aop"  

    xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"  

    xmlns:jpa="http://www.springframework.org/schema/data/jpa" 

    xmlns:websocket="http://www.springframework.org/schema/websocket"

    xmlns:security="http://www.springframework.org/schema/security"  

    xsi:schemaLocation="  

        http://www.springframework.org/schema/aop   

        http://www.springframework.org/schema/aop/spring-aop-4.0.xsd  

        http://www.springframework.org/schema/security   

        http://www.springframework.org/schema/security/spring-security-3.2.xsd  

        http://www.springframework.org/schema/beans   

        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd  

        http://www.springframework.org/schema/data/jpa   

        http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd  

        http://www.springframework.org/schema/tx   

        http://www.springframework.org/schema/tx/spring-tx-4.0.xsd  

        http://www.springframework.org/schema/context   

        http://www.springframework.org/schema/context/spring-context-4.0.xsd

        http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket.xsd">  

    <!-- 数据库配置文件位置 -->  

    <context:property-placeholder location="classpath:/jdbc.properties" />  

    <context:component-scan base-package="com.cn" /> 

    <!-- 配置c3p0数据源 -->  

    <bean id="parentDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">

<property name="driverClass" value="${jdbc.driverClassName}" />

<property name="user" value="${jdbc.username}"/>

<property name="password" value="${jdbc.password}" />

<property name="initialPoolSize" value="${c3p0.initialPoolSize}" />

<property name="maxPoolSize" value="${c3p0.maxPoolSize}" />

<property name="minPoolSize" value="${c3p0.minPoolSize}" />

<property name="maxStatements" value="${c3p0.maxStatements}" />

<property name="testConnectionOnCheckin" value="false" />

<property name="acquireRetryAttempts" value="5" />

<property name="acquireRetryDelay" value="2000" />

<property name="breakAfterAcquireFailure" value="false" />

</bean>  

  <bean id="localDataSource" parent="parentDataSource">

        <property name="jdbcUrl" value="${jdbc.url}"></property>

    </bean>

    <bean id="cnccDataSource" parent="parentDataSource">

        <property name="jdbcUrl" value="${jdbc.url1}"></property>

    </bean>

  <bean id="dataSource" class="com.cn.dynamicDS.DynamicDataSource">

        <property name="targetDataSources">

            <map key-type="java.lang.String">

                <entry value-ref="localDataSource" key="local"></entry>

                <entry value-ref="cnccDataSource" key="cncc"></entry>

            </map>

        </property>

        <property name="defaultTargetDataSource" ref="cnccDataSource"></property>

    </bean>

    <!-- 使用JDBC事物 -->  

    <bean id="transactionManager"  

        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">  

        <property name="dataSource" ref="dataSource" />  

    </bean>  

<!-- 使用annotation注解方式配置事务   -->

<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" />

     <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  

        <property name="dataSource" ref="dataSource" />  

        <property name="configLocation" value="classpath:sqlMapConfig.xml"></property> 

    </bean>  

    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">  

        <constructor-arg index="0" ref="sqlSessionFactory" />  

    </bean>

</beans>  

jdbc.properties:

jdbc.driverClassName=oracle.jdbc.driver.OracleDriver

jdbc.url=jdbc:oracle:thin:@localhost:1521:实例名

jdbc.username=用户名

jdbc.password=密码

jdbc.url1=jdbc:oracle:thin:@192.168.42.147:1521:第二个数据库实例名

#也可配置其他数据库

c3p0.initialPoolSize=10

c3p0.maxPoolSize=10

c3p0.minPoolSize=10

c3p0.maxStatements=10

常量类：

package com.cn.cncc.dynamicDS;

/**

 * 常量类

 * @author hjr

 *

 */

public class DataSourceConst {

/*

* 操作本地数据库

*/

    public static final String LOCAL = "local";

    /*

     * 操作BMC远端数据库

     */

    public static final String CNCC = "cncc";

}

动态数据源：

package com.cn.cncc.dynamicDS;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**

 * 动态数据源

 * @author hjr

 *

 */

public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override

    protected Object determineCurrentLookupKey() {

        // TODO Auto-generated method stub

        return DataSourceContextHolder.getDataSourceType();

    }

}

数据源动态切换方法类：

package com.cn.cncc.dynamicDS;

/**

 * 数据源切换方法类

 * @author hjr

 *

 */

public class DataSourceContextHolder {

    private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();//线程本地环境

    //设置数据源类型

    public static void  setDataSourceType(String dataSourceType)

    {

        contextHolder.set(dataSourceType);

    }

    //获取数据源类型

    public static String getDataSourceType()

    {

        return contextHolder.get();

    }

    //清除数据源类型

    public static void clearDataSourceType()

    {

        contextHolder.remove();

    }

}

测试类：

package test;

import java.io.BufferedReader;

import java.math.BigDecimal;

import java.sql.Clob;

import java.util.List;

import java.util.Map;

import org.apache.log4j.Logger;

import org.junit.Before;

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.cn.cncc.dynamicDS.DataSourceConst;

import com.cn.cncc.dynamicDS.DataSourceContextHolder;

import com.cn.cncc.service.CpuService;

public class dyanmicDataSourceTest {

Logger log = Logger.getLogger(dyanmicDataSourceTest.class);

    private CpuService cpuServiceImpl;

@Before

public void before(){

ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"classpath:applicationContext-servlet.xml","classpath:applicationContext.xml"});

cpuServiceImpl = (CpuService)context.getBean("cpuServiceImpl");

}

@Test

public void cpuTest(){

String dataSourceType = DataSourceContextHolder.getDataSourceType();//当前数据库

System.out.println(dataSourceType);

List<Object> findcpu = cpuServiceImpl.findCpuTop5();

if(null != findcpu && findcpu.size()>0){

try {

DataSourceContextHolder.setDataSourceType(DataSourceConst.LOCAL);//切换数据库

int insertcpu = cpuServiceImpl.insertCpuTop5(findcpu);//在另一个数据库查询

String dataSourceType2 = DataSourceContextHolder.getDataSourceType();

System.out.println(dataSourceType2);

} catch (Exception e) {

e.printStackTrace();

}

}

}

}

--------------------- 

作者：dewffgqd 

来源：CSDN 

原文：https://blog.csdn.net/dewffgqd/article/details/68060978 

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