資料源動态切換，主要思想是通過事先定義好的Key-Value進行動态擷取。主要使用了ThreadLocal和Spring AOP方式去串連起來。

spring為我們提供了資料源切換類org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource。

下附詳細代碼，供參考

github：https://github.com/AnnotationRoot/progresql_practice

目錄結構：

SSM手動、自動切換多資料源目錄結構：

友善學習的簡單的一個測試，jar版本自己定

配置檔案

spring.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:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       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/context
       http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop   http://www.springframework.org/schema/aop/spring-aop.xsd
        ">

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



        <context:property-placeholder location="classpath:/jdbc.properties"></context:property-placeholder>
        <!--postgres資料源配置-->
       <bean id="dataSourcePG" class="com.alibaba.druid.pool.DruidDataSource">
           <property name="driverClassName" value="${jdbc.driverClassName}"></property>
           <property name="url" value="${jdbc.url}"></property>
           <property name="username" value="${jdbc.username}"></property>
           <property name="password" value="${jdbc.password}"></property>
       </bean>

        <!--mysql資料源-->
    <bean id="dataSourceMSQL" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName1}"></property>
        <property name="url" value="${jdbc.url1}"></property>
        <property name="username" value="${jdbc.username1}"></property>
        <property name="password" value="${jdbc.password1}"></property>
    </bean>

    <bean id="dynamicDataSource" class="utils.DynamicDataSource">
        <property name="targetDataSources">
            <map key-type="java.lang.String">
                <entry key="dspg" value-ref="dataSourcePG"/>
                <entry key="dsmysql" value-ref="dataSourceMSQL"/>
            </map>
        </property>
        <!--預設資料源  postgresql-->
        <property name="defaultTargetDataSource" ref="dataSourcePG"/>
    </bean>


      <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
          <property name="dataSource" ref="dynamicDataSource"></property>
           <property name="typeAliasesPackage" value="com.lazy.entity"></property>
          <property name="mapperLocations">
              <list>
                  <value>
                      classpath:mapper/*.xml
                  </value>
              </list>
          </property>
      </bean>

      <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
          <property name="basePackage" value="com.lazy.dao"></property>
      </bean>

      <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
          <property name="dataSource" ref="dataSourceMSQL"></property>
      </bean>
        <!--注解管理事物-->
     <tx:annotation-driven transaction-manager="dataSourceTransactionManager"></tx:annotation-driven>

    <bean id="dataSourceExchange" class="utils.DataSourceExchange"/>
    <aop:config>
        <aop:aspect ref="dataSourceExchange">
            <aop:pointcut id="dataSourcePointcut" expression="execution(* com.lazy.service..*.*(..))"/>
            <aop:before pointcut-ref="dataSourcePointcut" method="before"/>
            <aop:after pointcut-ref="dataSourcePointcut" method="after"/>
        </aop:aspect>
    </aop:config>


</beans>

jdbc.properties

# MySQL
jdbc.driverClassName1=com.mysql.jdbc.Driver
jdbc.url1=jdbc:mysql://localhost:3306/mytest
jdbc.username1=root
jdbc.password1=123456

# PostgreSQL
jdbc.driverClassName=org.postgresql.Driver
jdbc.url=jdbc:postgresql://127.0.0.1:5432/postgres
jdbc.username=postgres
jdbc.password=123456

springMVC.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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">

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


    <!--添加swagger配置-->
    <bean class="com.swagger.MySwaggerConfig"></bean>
    <bean class="springfox.documentation.swagger2.configuration.Swagger2DocumentationConfiguration" id="swagger2Config"/>
    <mvc:resources location="classpath:/META-INF/resources/" mapping="swagger-ui.html"/>
    <mvc:resources location="classpath:/META-INF/resources/webjars/" mapping="/webjars/**"/>


    <mvc:annotation-driven>
            <!--<mvc:message-converters>
                <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                    <property name="supportedMediaTypes">
                    <list>
                        <value>application/json</value>
                    </list>
                    </property>
                </bean>
            </mvc:message-converters>-->
        </mvc:annotation-driven>

        <!--視圖解析-->
        <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/"></property>
            <property name="suffix" value=".jsp"></property>
        </bean>

</beans>

mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.lazy.dao.PostgresqlDao">

    <select id="selectAll" resultType="MyTest">
     SELECT * from t_mytest
    </select>

</mapper>

pom.xml

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.lazy</groupId>
  <artifactId>progresql</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>progresql Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <!-- spring版本号 -->
    <spring.version>4.2.5.RELEASE</spring.version>
    <!-- mybatis版本号 -->
    <mybatis.version>3.2.8</mybatis.version>
    <!-- mysql驅動版本号 -->
    <mysql-driver.version>5.1.29</mysql-driver.version>
    <!-- log4j日志包版本号 -->
    <slf4j.version>1.7.18</slf4j.version>
    <log4j.version>1.2.17</log4j.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
      <!-- scope=compile 的情況（預設compile），也就是說這個項目在編譯、測試，運作階段都需要這個artifact對應的jar包在classpath中 -->
      <!-- scope=provided ，則可以認為這個provided是目标容器已經provided這個artifact,它隻影響到編譯、測試階段，運作階段，假定目标容器已經提供了這個jar包 -->
      <scope>provided</scope>
    </dependency>

    <!-- 添加jstl依賴 -->
    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>

    <!-- 添加junit4依賴 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <!-- 指定範圍，在測試時才會加載 -->
      <scope>test</scope>
    </dependency>

    <!-- 添加spring核心依賴 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-oxm</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!-- 添加mybatis依賴 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>${mybatis.version}</version>
    </dependency>

    <!-- 添加mybatis/spring整合包依賴 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.2.2</version>
    </dependency>

    <!-- 添加mysql驅動依賴 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>${mysql-driver.version}</version>
    </dependency>

    <!-- postgreSQL核心包 資料庫版本9.X-->
<!--    <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <version>9.3-1102-jdbc4</version>
    </dependency>
    <dependency>
      <groupId>org.apache.tomcat</groupId>
      <artifactId>tomcat-jdbc</artifactId>
      <version>8.0.9</version>
    </dependency>-->

    <!-- postgreSQL核心包 資料庫版本10.X-->
    <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
    <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <version>42.2.5</version>
    </dependency>

    <!--springfox的核心jar包-->
    <dependency>
      <groupId>io.springfox</groupId>
      <artifactId>springfox-swagger2</artifactId>
      <version>2.7.0</version>
    </dependency>
    <!--springfox-ui的jar包(裡面包含了swagger的界面靜态檔案)-->
    <dependency>
      <groupId>io.springfox</groupId>
      <artifactId>springfox-swagger-ui</artifactId>
      <version>2.7.0</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/aspectj/aspectjweaver -->
    <dependency>
      <groupId>aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.5.3</version>
    </dependency>

    <!-- 添加資料庫連接配接池依賴 -->
    <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.3</version>
    </dependency>

    <!-- 添加fastjson -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.1.41</version>
    </dependency>


    <!-- 添加日志相關jar包 -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>${log4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>${slf4j.version}</version>
    </dependency>

    <!-- log end -->

    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.0</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.7.25</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-classic</artifactId>
      <version>1.2.3</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-api -->
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <version>5.2.0</version>
      <scope>test</scope>
    </dependency>




    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.1</version>
    </dependency>

    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
    </dependency>

    <dependency>
      <groupId>commons-codec</groupId>
      <artifactId>commons-codec</artifactId>
      <version>1.9</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.4.3</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.4.3</version>
    </dependency>
  </dependencies>

  <build>
    <finalName>progresql</finalName>
  </build>
</project>

web.xml

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:spring.xml</param-value>
  </context-param>
  <filter>
    <filter-name>encoding</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
    <init-param>
      <param-name>forceEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>encoding</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springMVC.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

</web-app>

工具類

DataSourceEnum

package utils;

/**
 * Created by JSKJ on 2019/5/13.
 */
public enum DataSourceEnum {
    DSPG("dspg"), DSMYSQL("dsmysql");

    private String key;

    DataSourceEnum(String key) { this.key = key; }

    public String getKey() { return key; }

    public void setKey(String key) {  this.key = key; }
}

DataSourceExchange

package utils;

import org.aspectj.lang.JoinPoint;

/**
 * Created by JSKJ on 2019/5/13.
 */
public class DataSourceExchange {

    public void before(JoinPoint point) {

        //擷取目标對象的類類型
        Class<?> aClass = point.getTarget().getClass();
        String c = aClass.getName();
        String[] ss = c.split("\\.");
        //擷取包名用于區分不同資料源
        String packageName = ss[3];

        if ("product".equals(packageName)) {
            DataSourceHolder.setDataSources(DataSourceEnum.DSPG.getKey());
            System.out.println("資料源："+DataSourceEnum.DSPG.getKey());
        } else {
            DataSourceHolder.setDataSources(DataSourceEnum.DSMYSQL.getKey());
            System.out.println("資料源："+DataSourceEnum.DSMYSQL.getKey());
        }
    }

    /**
     * 執行後将資料源置為空
     */
    public void after() {
        DataSourceHolder.setDataSources(null);
    }

}

DataSourceHolder

package utils;

/**
 * Created by JSKJ on 2019/5/13.
 * DynamicDataSourceHolder用于持有目前線程中使用的資料源辨別
 */
public class DataSourceHolder {

    private static final ThreadLocal<String> dataSources = new ThreadLocal<String>();

    public static void setDataSources(String dataSource) {
        dataSources.set(dataSource);
    }

    public static String getDataSources() {
        return dataSources.get();
    }

}

DynamicDataSource

package utils;

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

/**
 * Created by JSKJ on 2019/5/13.
 */
public class DynamicDataSource extends AbstractRoutingDataSource {

    protected Object determineCurrentLookupKey() {
        return DataSourceHolder.getDataSources();
    }
}

基本配置完成後，做個簡單的測試

ServiceImpl

此處動态切換資料源是基于不同的package名稱來實作（參考頂部目錄）

這裡product裡資料源為postgres，mysql包下的資料源為mysql

PostgresqlServiceImpl

package com.lazy.service.product.impl;

import com.lazy.dao.PostgresqlDao;
import com.lazy.service.product.PostgresqlService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import utils.DataSourceEnum;
import utils.DataSourceHolder;

import java.util.List;

/**
 * Created by JSKJ on 2019/5/10.
 */
@Service
@Slf4j
public class PostgresqlServiceImpl implements PostgresqlService {
    @Autowired
    private PostgresqlDao dao;


    public List selectAll() {
        
     //   DataSourceHolder.setDataSources(DataSourceEnum.DSMYSQL.getKey()); // 若需手動指定資料源用這個
        log.debug("PostgresqlDao=====dao=========="+dao);
        return dao.selectAll();
    }
}

MysqlImpl

package com.lazy.service.mysql.impl;

import com.lazy.dao.PostgresqlDao;
import com.lazy.service.mysql.MysqlService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


import java.util.List;

/**
 * Created by JSKJ on 2019/5/14.
 */
@Service
@Slf4j
public class MysqlImpl implements MysqlService {

    @Autowired
    private PostgresqlDao dao;

    public List selectAll() {
        return dao.selectAll();
    }
}

Controller

package com.lazy.controller;

import com.lazy.service.mysql.MysqlService;
import com.lazy.service.product.PostgresqlService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import utils.BaseMsg;
import utils.SuccessMsg;

import java.util.List;

/**
 * Created by JSKJ on 2019/5/10.
 */
@Controller
@RequestMapping("/aa")
@Api(tags = "aa",description = "測試")
public class PostgresqlController {

    @Autowired
    private PostgresqlService service;

    @Autowired
    private MysqlService mysqlService;

    @ResponseBody
    @RequestMapping(value = "api/Postgrestest",method = RequestMethod.GET)
    @ApiOperation(value = "測試清單")
 //   @ApiImplicitParam(paramType = "query", name = "", value = "", required = true, dataType = "")
    public BaseMsg readAll1(){

        List list = service.selectAll();
        return new SuccessMsg(list);
    }

    @ResponseBody
    @RequestMapping(value = "api/Mysqltest",method = RequestMethod.GET)
    @ApiOperation(value = "測試清單")
    //   @ApiImplicitParam(paramType = "query", name = "", value = "", required = true, dataType = "")
    public BaseMsg readAll2(){

        List list = mysqlService.selectAll();
        return new SuccessMsg(list);
    }

}

請求示例

mysql裡的資料（時間格式請忽略）

SSM手動、自動切換多資料源目錄結構：

postgres裡的資料

SSM手動、自動切換多資料源目錄結構：

SSM手動、自動切換多資料源目錄結構：

目錄結構：

配置檔案

spring.xml

jdbc.properties

springMVC.xml

mapper.xml

pom.xml

web.xml

工具類

DataSourceEnum

DataSourceExchange

DataSourceHolder

DynamicDataSource

基本配置完成後，做個簡單的測試

ServiceImpl

MysqlImpl

請求示例

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