170615、spring不同数据库数据源动态切换

spring mvc+mybatis+多数据源切换 选取Oracle,MySQL作为例子切换数据源。mysql为默认数据源，在测试的action中，进行mysql和oracle的动态切换。

1、web.xml配置

<context-param>
    <param-name>webAppRootKey</param-name>
    <param-value>trac</param-value>
</context-param>

<!-- Spring的log4j监听器 -->
<listener>
    <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>

<!-- 字符集 过滤器 -->
<filter>
    <filter-name>CharacterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>utf8</param-value>
    </init-param>
    <init-param>
        <param-name>forceEncoding</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<!-- Spring view分发器 -->
<servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/dispatcher.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>*.action</url-pattern>
</servlet-mapping>

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

2、dispatcher.xm

<mvc:annotation-driven />
<context:component-scan base-package="com.trac" />

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

<!-- freemarker config -->
<bean id="freemarkerConfig" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
    <property name="templateLoaderPath" value="/WEB-INF/freemarker/" />
    <property name="freemarkerVariables">
        <map>
            <entry key="xml_escape" value-ref="fmXmlEscape" />
        </map>
    </property>
    <property name="freemarkerSettings">
        <props>
            <prop key="defaultEncoding">UTF-8</prop>
        </props>
    </property>
</bean>

<bean id="fmXmlEscape" class="freemarker.template.utility.XmlEscape" />

<!-- View resolvers can also be configured with ResourceBundles or XML files.
    If you need different view resolving based on Locale, you have to use the
    resource bundle resolver. -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
    <property name="exposeRequestAttributes" value="true" />
    <property name="exposeSessionAttributes" value="true" />
    <property name="exposeSpringMacroHelpers" value="true" />
    <property name="contentType" value="text/html;charset=UTF-8" />
    <property name="cache" value="true" />
    <property name="prefix" value="" />
    <property name="suffix" value=".ftl" />
</bean>

3、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:tx="http://www.springframework.org/schema/tx"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

   <bean id="parentDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"></bean>

   <bean id="mySqlDataSource" parent="parentDataSource">
      <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
      <property name="url" value="jdbc:mysql://localhost:3306/icbc_wx"></property>
      <property name="username" value="root"></property>
      <property name="password" value="root"></property>
   </bean>

   <bean id="oracleDataSource" parent="parentDataSource">
      <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
      <property name="url" value="jdbc:oracle:thin:@192.168.1.168:1521:orcl"></property>
      <property name="username" value="zcgd"></property>
      <property name="password" value="zcgd"></property>
   </bean>

   <!--多数据源-->
   <bean id="dataSource" class="com.strongunion.common.datasource.DataSources">
      <property name="targetDataSources">
         <map key-type="java.lang.String">
            <entry value-ref="mySqlDataSource" key="MYSQL"></entry>
            <entry value-ref="oracleDataSource" key="ORACLE"></entry>
         </map>
      </property>
      <property name="defaultTargetDataSource" ref="mySqlDataSource"></property>
   </bean>

   <!--单一数据源-->
   <!--<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
      init-method="init" destroy-method="close">
      &lt;!&ndash; 基本属性 url、user、password &ndash;&gt;
      <property name="url" value="${jdbc.url}" />
      <property name="username" value="${jdbc.username}" />
      <property name="password" value="${jdbc.password}" />

      &lt;!&ndash; 配置初始化大小、最小、最大 &ndash;&gt;
      <property name="initialSize" value="1" />
      <property name="minIdle" value="1" />
      <property name="maxActive" value="20" />

      &lt;!&ndash; 配置获取连接等待超时的时间 &ndash;&gt;
      <property name="maxWait" value="60000" />

      &lt;!&ndash; 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 &ndash;&gt;
      <property name="timeBetweenEvictionRunsMillis" value="60000" />

      &lt;!&ndash; 配置一个连接在池中最小生存的时间，单位是毫秒 &ndash;&gt;
      <property name="minEvictableIdleTimeMillis" value="300000" />

      <property name="validationQuery" value="SELECT 'x'" />
      <property name="testWhileIdle" value="true" />
      <property name="testOnBorrow" value="false" />
      <property name="testOnReturn" value="false" />

      &lt;!&ndash; 打开PSCache，并且指定每个连接上PSCache的大小 &ndash;&gt;
      <property name="poolPreparedStatements" value="true" />
      <property name="maxPoolPreparedStatementPerConnectionSize" value="20" />

      &lt;!&ndash; 打开removeAbandoned功能 &ndash;&gt;
      <property name="removeAbandoned" value="true" />
       &lt;!&ndash; 1800秒，也就是30分钟 &ndash;&gt;
       <property name="removeAbandonedTimeout" value="1800" />
       &lt;!&ndash; 关闭abanded连接时输出错误日志 &ndash;&gt;
       <property name="logAbandoned" value="true" />

      &lt;!&ndash; 配置监控统计拦截的filters &ndash;&gt;
      <property name="filters" value="stat" />
   </bean>-->

   <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <property name="dataSource" ref="dataSource" />
   </bean>
   <tx:annotation-driven transaction-manager="transactionManager" />

   <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
      <property name="dataSource" ref="dataSource" />
      <property name="configLocation" value="classpath:mybatis-config.xml" />
   </bean>

   <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
      <constructor-arg ref="sqlSessionFactory" />
   </bean>
</beans>

4、DataSourceInstances.java

package com.strongunion.common.datasource;

/**
 * Desc :  定义数据源的标识, 和applicationContext.xml中 DataSources 的 targetDataSources 的key对应
 * User : RICK
 * Time : 2017/8/18 9:41
  */

public class DataSourceInstances {
    /**mysql数据源*/
    public static final String MYSQL="MYSQL";
    /**oralce数据源*/
    public static final String ORACLE="ORACLE";
}

5、DataSourceSwitch.java

package com.strongunion.common.datasource;

/**
 * Desc :  切换数据源开关
 * User : RICK
 * Time : 2017/8/18 10:49
  */

public class DataSourceSwitch {

    private static final ThreadLocal contextHolder=new ThreadLocal();

    public static void setDataSourceType(String dataSourceType){
        contextHolder.set(dataSourceType);
    }

    public static String getDataSourceType(){
        return (String) contextHolder.get();
    }

    public static void clearDataSourceType(){
        contextHolder.remove();
    }
}

6、DataSources.java

package com.strongunion.common.datasource;

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

/**
 * Desc :  配置于applicationContext 中，线程局部变量ThreadLocal contextHolder
 *  保存当前需要的数据源类型，当 DataSourceSwitch. setDataSourceType(DataSourceInstances.XXX)
 *  保存当前需要的数据源类型的时候，DataSources 会从当前线程中查找线程变量的数据源类型，从而决定使用何种数据源
 * User : RICK
 * Time : 2017/8/18 9:43
  */

public class DataSources extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DataSourceSwitch.getDataSourceType();
    }
}

7、测试类TestController.java

package com.strongunion.apps.controller;

import com.strongunion.apps.service.IUserService;
import com.strongunion.common.ResultJson;
import com.strongunion.common.datasource.DataSourceInstances;
import com.strongunion.common.datasource.DataSourceSwitch;
import com.strongunion.generator.entity.User;
import com.strongunion.utils.Util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.List;

/**
 * Desc :  测试数据源
 * User : RICK
 * Time : 2017/8/18 9:27
  */

@RestController
@RequestMapping("/demo")
public class TestController {

    private static final Logger log = LoggerFactory.getLogger(TestController.class);

    @Resource
    private IUserService userService;

    @RequestMapping(value = "/index", method = RequestMethod.GET)
    public String index(){
        return "hello";
    }

    @RequestMapping(value = "/db/{type}", method = RequestMethod.GET)
    public ResultJson testDataBase(@PathVariable("type") String type) throws Exception{
        ResultJson resultJson  =  null;
        if (Util.isNotNull(type)){
            if(DataSourceInstances.MYSQL.equals(type)){
                DataSourceSwitch.setDataSourceType(DataSourceInstances.MYSQL);
            } else if(DataSourceInstances.ORACLE.equals(type)){
                DataSourceSwitch.setDataSourceType(DataSourceInstances.ORACLE);
            }
        } else {
            DataSourceSwitch.setDataSourceType(DataSourceInstances.MYSQL);
        }
        List<User> userList = userService.queryAllUsers();
        log.info("userList------------------------------>" + userList);
        resultJson = ResultJson.buildSuccessInstance(userList);
        return resultJson;
    }
}

8、运行效果

mysql数据库

oralce数据库

mysql数据源

oracle数据源