SSM配置动态数据源

　　多数据源配置主要涉及自定义类（DataSource注解类、DataSourceAspect切面类，动态数据源接口实现类、以及数据源字符串线程保存类），pom.xml文件、applicationContext.xml、mybatis相关配置，以及业务代码(test包)，参考实际开发及网上资料记录下来。

一、配置文件

　　1.pom.xml

　　这里我用的是mac上的eclipse，maven版本是3.6.0，jdk版本是1.8，tomcat9。pom文件配置如下:

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>laboratory</groupId>
  <artifactId>mvclab</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>mcv Maven Webapp</name>
  <url>http://maven.apache.org</url>
  
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <spring.version>5.1.5.RELEASE</spring.version>
        <mybatis.version>3.2.8</mybatis.version>
        <mybatis-spring.version>1.2.2</mybatis-spring.version>
        <spring-jpa-version>1.3.2.RELEASE</spring-jpa-version>
    </properties>
  
  <dependencies>
          <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!--spring-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</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-beans</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-orm</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-aspects</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-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!--日志-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

        <!--tomcat所需jar包-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.24</version>
        </dependency>
        
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>2.2.2</version>
        </dependency>

        <!--返回object对象所需要的依赖，它在<mvc:annotation-driven>注册时注入-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
        
        <!-- 补充 -->
        <!-- https://mvnrepository.com/artifact/aopalliance/aopalliance -->
        <dependency>
            <groupId>aopalliance</groupId>
            <artifactId>aopalliance</artifactId>
            <version>1.0</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.13</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjrt -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.8.9</version>
        </dependency>  
        
        
        <!-- MyBatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>${mybatis-spring.version}</version>
        </dependency>
        <!-- dbcp数据源 -->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.26</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.20</version>
            <scope>provided</scope>
        </dependency>
  </dependencies>
  <build>
    <finalName>mcv</finalName>
  </build>
</project>

　　2.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"  
    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/aop 
        http://www.springframework.org/schema/aop/spring-aop.xsd">

    <!-- context:设置注解扫描包注解
        注: 如果springmvc-servlet中扫描注解没有排除@Service注解，这里要设置扫描除@Controller之外的其它所有注解
     -->
    <context:component-scan base-package="com.mvc">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
        <!-- 自定义异常处理 -->
        <context:exclude-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice" />
    </context:component-scan>
    
    <!-- 开启@Autowired注解扫描
        注: 它等价于<bean class="org.springframework.beans.factory.annotation. AutowiredAnnotationBeanPostProcessor "/> 
        注: 配置了<context:component-scan />，默认包含对@Autowired的配置，因此下面这个配置就不需要了
     -->
    <context:annotation-config/>
    
    <!-- 注册数据源配置文件 -->
    <context:property-placeholder location="classpath:jdbc.properties" />
    <!-- 注册数据源对象 这里用Spring内置数据源 -->
    <bean id="dataSource1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName">
            <value>${oracle11g.driverClass}</value>
        </property>
        <property name="url">
            <value>${oracle11g.url}</value>
        </property>
        <property name="username">
            <value>${oracle11g.username}</value>
        </property>
        <property name="password">
            <value>${oracle11g.password}</value>
        </property>
        <property name="maxActive">
            <value>${oracle11g.maxActive}</value>
        </property>
        <property name="maxIdle">
            <value>${oracle11g.maxIdle}</value>
        </property>
        <property name="maxWait">
            <value>${oracle11g.maxWait}</value>
        </property>
        <property name="defaultAutoCommit">
            <value>${oracle11g.defaultAutoCommit}</value>
        </property>
        <property name="timeBetweenEvictionRunsMillis">
            <value>${oracle11g.timeBetweenEvictionRunsMillis}</value>
        </property>
        <property name="minEvictableIdleTimeMillis">
            <value>${oracle11g.minEvictableIdleTimeMillis}</value>
        </property>
    </bean>
    <bean id="dataSource2" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close">
        <property name="driverClassName">
            <value>${oracle11g-1.driverClass}</value>
        </property>
        <property name="url">
            <value>${oracle11g-1.url}</value>
        </property>
        <property name="username">
            <value>${oracle11g-1.username}</value>
        </property>
        <property name="password">
            <value>${oracle11g-1.password}</value>
        </property>
        <property name="maxActive">
            <value>${oracle11g-1.maxActive}</value>
        </property>
        <property name="maxIdle">
            <value>${oracle11g-1.maxIdle}</value>
        </property>
        <property name="maxWait">
            <value>${oracle11g-1.maxWait}</value>
        </property>
        <property name="defaultAutoCommit">
            <value>${oracle11g-1.defaultAutoCommit}</value>
        </property>
        <property name="timeBetweenEvictionRunsMillis">
            <value>${oracle11g-1.timeBetweenEvictionRunsMillis}</value>
        </property>
        <property name="minEvictableIdleTimeMillis">
            <value>${oracle11g-1.minEvictableIdleTimeMillis}</value>
        </property>
    </bean>
    <!-- 配置动态数据源 -->
    <bean id="dynamicDataSource" class="com.mvc.dynamicDataSource.DynamicDataSource">
        <property name="targetDataSources">  
              <map key-type="java.lang.String">
                  <!-- 指定lookupKey和与之对应的数据源 -->
                  <entry key="dataSource1" value-ref="dataSource1" />
                  <entry key="dataSource2" value-ref="dataSource2" />
              </map>  
          </property>  
          <!-- 指定默认的数据源 -->
          <property name="defaultTargetDataSource" ref="dataSource1" /> 
    </bean>
    
    <!-- 配置事务管理对象,注意这里设置的是dataSource1而不是dynamicDataSource--> 
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource1" />
    </bean>
    <!-- 将所有具有@Transactional注解的Bean自动配置为声明式事务支持 --> 
    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>

    <!-- MyBatis 数据源和sql- -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dynamicDataSource"/>
        <property name="mapperLocations" value="classpath:/mappings/**/*.xml"/>
        <property name="configLocation" value="classpath:/mybatis-config.xml"></property>
    </bean>
    <!-- MyBayis 扫描器配置-->
    <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.mvc.laboratory"/>
    </bean>
    
    <!--接收json数据-->
    <bean id="jsonHttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>application/json;charset=UTF-8</value>
            </list>
        </property>
    </bean>
    
    <!-- 配置事务自动代理 -->
    <aop:aspectj-autoproxy proxy-target-class="true" />
</beans>

　　3.mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!-- 全局参数 -->
    <settings>
        <!-- 使全局的映射器启用或禁用缓存。 -->
        <setting name="cacheEnabled" value="true"/>
        <!-- 全局启用或禁用延迟加载。当禁用时，所有关联对象都会即时加载。 -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- 当启用时，有延迟加载属性的对象在被调用时将会完全加载任意属性。否则，每种属性将会按需要加载。 -->
        <setting name="aggressiveLazyLoading" value="true"/>
        <!-- 是否允许单条sql 返回多个数据集  (取决于驱动的兼容性) default:true -->
        <setting name="multipleResultSetsEnabled" value="true"/>
        <!-- 是否可以使用列的别名 (取决于驱动的兼容性) default:true -->
        <setting name="useColumnLabel" value="true"/>
        <!-- 允许JDBC 生成主键。需要驱动器支持。如果设为了true，这个设置将强制使用被生成的主键，有一些驱动器不兼容不过仍然可以执行。  default:false  -->
        <setting name="useGeneratedKeys" value="false"/>
        <!-- 指定 MyBatis 如何自动映射 数据基表的列 NONE：不隐射　PARTIAL:部分  FULL:全部  -->  
        <setting name="autoMappingBehavior" value="PARTIAL"/>
        <!-- 这是默认的执行类型  （SIMPLE: 简单； REUSE: 执行器可能重复使用prepared statements语句；BATCH: 执行器可以重复执行语句和批量更新）  -->
        <setting name="defaultExecutorType" value="SIMPLE"/>
        <!-- 使用驼峰命名法转换字段。
            <setting name="mapUnderscoreToCamelCase" value="true"/> 
        -->
        <!-- 设置本地缓存范围 session:就会有数据的共享  statement:语句范围 (这样就不会有数据的共享 ) defalut:session -->
        <setting name="localCacheScope" value="SESSION"/>
        <!-- 设置但JDBC类型为空时,某些驱动程序 要指定值,default:OTHER，插入空值时不需要指定类型 -->
        <setting name="jdbcTypeForNull" value="NULL"/>
        <!-- mybatis打印日志 -->
        <!-- <setting name="logImpl" value="STDOUT_LOGGING" /> -->    
        <setting name="logImpl" value="NO_LOGGING" />
    </settings>
    
    <!-- 类型别名 -->
    <typeAliases>
    </typeAliases>
    
</configuration>

　　4.jdbc.properties和log4j.properties

　　这里我用的是oracle，在mac上用docker起了两个oracle数据库镜像，端口分别映射到本地mac的1521和1522，并且各自建了apple账号。

# docker ps --> oracle11g
oracle11g.driverClass=oracle.jdbc.driver.OracleDriver
oracle11g.url=jdbc:oracle:thin:@127.0.0.1:1521:helowin
oracle11g.username=apple
oracle11g.password=1234
oracle11g.maxActive=100
oracle11g.maxIdle=40
oracle11g.maxWait=3000
oracle11g.defaultAutoCommit=true
oracle11g.timeBetweenEvictionRunsMillis=3600000
oracle11g.minEvictableIdleTimeMillis=3600000

# docker ps --> oracle11g-1
oracle11g-1.driverClass=oracle.jdbc.driver.OracleDriver
oracle11g-1.url=jdbc:oracle:thin:@127.0.0.1:1522:helowin
oracle11g-1.username=apple
oracle11g-1.password=1234
oracle11g-1.maxActive=100
oracle11g-1.maxIdle=40
oracle11g-1.maxWait=3000
oracle11g-1.defaultAutoCommit=true
oracle11g-1.timeBetweenEvictionRunsMillis=3600000
oracle11g-1.minEvictableIdleTimeMillis=3600000

log4j.rootCategory=info, CONSOLE, DAILY
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-5p[%F:%M:%L]- %m%n
log4j.appender.DAILY=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DAILY.DatePattern='.'yyyy-MM-dd
log4j.appender.DAILY.ImmediateFlush=true
log4j.appender.DAILY.Append=true
log4j.appender.DAILY.layout=org.apache.log4j.PatternLayout
log4j.appender.DAILY.layout.conversionPattern=[ %-5p]-%-d{yyyyMMdd HHmmss}-[%F:%M:%L]- %m%n
log4j.appender.DAILY.File=../logs/mvc.log

　　5.springmvc.xml配置

<?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"
       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/aop
            http://www.springframework.org/schema/aop/spring-aop.xsd
            http://www.springframework.org/schema/tx
            http://www.springframework.org/schema/tx/spring-tx.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc.xsd
">
    <mvc:annotation-driven>
        <!-- 解决乱码 -->
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8" />
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>
    <!-- 设置注解扫描目录
        注意，在springmvc-servlet中排除了@Service注解,它等价于在applicationContext.xml中排除@Controller注解
        SpringMVC中扫描controller而不是@Service，因为此时service还没有进行事务处理可能会引起事务失效
     -->
    <context:component-scan base-package="com.mvc" >
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service" />
    </context:component-scan>
    
    <!-- 静态资源访问控制 -->
    <mvc:resources mapping="/images/**" location="/images/" />
    <mvc:resources mapping="/js/**" location="/js/" />
    <mvc:resources mapping="/css/**" location="/css/" />
</beans>

　　6.web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0"
>

  <display-name>Archetype Created Web Application</display-name>
  <!-- 注册ApplicationContext容器 -->
      <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
     <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    
  <!--注册中央调度器-->
  <servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
  </servlet>
  <servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
      <welcome-file>welcome.jsp</welcome-file>
    </welcome-file-list>

  <!--解决requesMapping请求参数中的中文乱码-->
  <filter>
    <filter-name>encodingFilter</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>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>

二、自定义类

　　1.DataSource

package com.mvc.dynamicDataSource;

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;

@Target({ ElementType.TYPE,ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
    String value() default DataSource.dataSource1;
    public static String dataSource1 = "dataSource1";
    public static String dataSource2 = "dataSource2";
}

　　2.DataSourceAspect

package com.mvc.dynamicDataSource;

import java.lang.reflect.Method;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

@Component
@Aspect
@Order(1)
public class dataSourceAspect {
    
    @Pointcut(value="execution(* com.mvc.laboratory..*.*(..))")
    private void doPointcut() {};
    
    @Before(value = "doPointcut()")
    @After(value = "doPointcut()")
    public void intercept(JoinPoint joinPoint) throws NoSuchMethodException {
        // 获取切入点的类反射
        Class<?> targetClass = joinPoint.getTarget().getClass();
        // 获取方法参数
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        for (Class<?> clazz:targetClass.getInterfaces()){
            dealDataSource(clazz, signature.getMethod());
        }
        // 默认使用目标类的注解，如果没有则使用其实现的接口注解
        dealDataSource(targetClass, signature.getMethod());
    }
    
    private void dealDataSource(Class<?> clazz, Method method) throws NoSuchMethodException {
        // 获取方法参数
        Class<?>[] paramTypeArr = method.getParameterTypes();
        // 检查是否为dataSource注解
        if (clazz.isAnnotationPresent(DataSource.class)){
            // 获取注解对象
            DataSource source = clazz.getAnnotation(DataSource.class);
            DynamicDataSourceHolder.setDataSource(source.value());
        }
        Method m = clazz.getMethod(method.getName(), paramTypeArr);
        if (m != null && m.isAnnotationPresent(DataSource.class)) {
            DataSource source = m.getAnnotation(DataSource.class);
            DynamicDataSourceHolder.setDataSource(source.value());
        }
    }
}

　　3.DynamicDataSource

package com.mvc.dynamicDataSource;

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

/**
 * 通过重写这个查找数据源标识的方法就可以让spring切换到指定的数据源 *
 */
public class DynamicDataSource extends AbstractRoutingDataSource{
    @Override
    protected Object determineCurrentLookupKey() {
        // 从自定义的位置获取数据源标识
        return DynamicDataSourceHolder.getDataSource();
    }
}

　　4.DynamicDataSourceHolder

package com.mvc.dynamicDataSource;

/**
 * 用于持有当前线程中使用的数据源标识
 */
public class DynamicDataSourceHolder {
    // 注意：数据源标识保存在线程变量中，避免多线程操作数据源时互相干扰
      private static final ThreadLocal<String> THREAD_DATA_SOURCE = new ThreadLocal<>();
 
      public static String getDataSource() {
          return THREAD_DATA_SOURCE.get();
      }
     public static void setDataSource(String dataSource) {
         THREAD_DATA_SOURCE.set(dataSource);
     }
     public static void clearDataSource() {
         THREAD_DATA_SOURCE.remove();
     }
}

三、业务代码

　　1.TestController

package com.mvc.laboratory.test;

import java.util.List;
import java.util.Map;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping(value = "/test")
public class TestController {
    
    @Resource
    private TestService testService;
    
    /**
     * @see http://localhost:8080/mvclab/test/testAspectJAround?name=weiweian&age=123
     * @param name
     * @param age
     * @return
     */
    @RequestMapping(value = "/testAspectJAround")
    @ResponseBody
    public List<Map<String, String>> testAspectJArounds(HttpServletRequest request, String name, String age){
        List<Map<String, String>> map = testService.testAspectJAround(request, name, age);
        return map;
    }
    /**
     * @see http://localhost:8080/mvclab/test/testDynamicDataSource
     * @param request
     * @return
     */
    @RequestMapping(value = "/testDynamicDataSource")
    @ResponseBody
    public List<Map<String, String>> testDynamicDataSource(HttpServletRequest request){
        List<Map<String, String>> map = testService.testDynamicDataSource(request);
        return map;
    }
}

　　2.TestService

package com.mvc.laboratory.test;

import java.util.List;
import java.util.Map;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
@Transactional(rollbackFor = Exception.class)
public class TestService {
    
    @Resource
    private LoggerDao loggerDao;
    @Resource
    private TestDao testDao;
    
    public List<Map<String, String>> testAspectJAround(HttpServletRequest request, String name, String age) {
        List<Map<String, String>> map = loggerDao.test();
        return map;
    }

    public List<Map<String, String>> testDynamicDataSource(HttpServletRequest request) {
        List<Map<String, String>> map = testDao.dynamicDataSource();
        return map;
    }
}

　　3.LoggerDao

package com.mvc.laboratory.test;

import java.util.Date;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.Param;

import com.mvc.dynamicDataSource.DataSource;

@DataSource(DataSource.dataSource1)
public interface LoggerDao {
    public List<Map<String, String>> test();
}

　　4.TestDao

package com.mvc.laboratory.test;

import java.util.List;
import java.util.Map;

import com.mvc.dynamicDataSource.DataSource;

@DataSource(DataSource.dataSource2)
public interface TestDao {
    public List<Map<String, String>> dynamicDataSource();
}

 　　5.logger.xml和test.xml

　　参考applicationcontext.xml中关于mabatis的配置，目录为resources/mappings/test/logger.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.mvc.laboratory.test.LoggerDao">
    
    <select id="test" resultType="java.util.Map">
        select 
            url, 
            intfname, 
            sign, 
            to_char(begin_time) as begin_time, 
            to_char(end_time) as end_time, 
            result
         from intf_caller_log
    </select>
            
</mapper>

<?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.mvc.laboratory.test.TestDao">
    
    <select id="dynamicDataSource" resultType="java.util.Map">
        select * from test
    </select>
            
</mapper>

　　6.intf_caller_log和test表

　　参考LoggerDao的注解，intf_caller_log表位于dataSource1数据源对应的数据库中，test表位于dataSource2数据源对应的数据库中，两个表只是查询，可自由创建。

四、测试

　　1.单元测试

　　在test/mvc路径下新建测试类，内容如下：

package mvc;

import java.util.List;
import java.util.Map;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import com.mvc.laboratory.test.LoggerDao;
import com.mvc.laboratory.test.TestDao;

@RunWith(SpringJUnit4ClassRunner.class) 
@ContextConfiguration({"classpath:applicationContext.xml"})
@Transactional(rollbackFor = Exception.class)
public class DynamicDataSourceTest {
    
    @Resource
    private LoggerDao loggerDao;
    
    @Resource
    private TestDao testDao;
    
    @Test
    public void loggerTest() {
        List<Map<String, String>> map = loggerDao.test();
        for (int i = 0; i < map.size(); i++) {
            System.out.println(map.get(i));
        }
    }
    
    @Test
    public void dynamicDataSourceTest() {
        List<Map<String, String>> map = testDao.dynamicDataSource();
        for (int i = 0; i < map.size(); i++) {
            System.out.println(map.get(i));
        }
    }
}

　　分别执行两个方法（run as junit，可在run configuration中配置要执行的方法及junit版本(这里是4)），打印如下：

...
{INTFNAME=@82c0502, END_TIME=2019-06-26 09:44:04.0, BEGIN_TIME=2019-06-26 09:44:04.0, ID=8C312E309096C199E05011AC02001066, SIGN=1, RESULT={sayHello=hello, my name is weiweian, 123 years old., name=weiweian, age=123}, URL=/mvclab/test/example1}
{INTFNAME=@784a89d9, END_TIME=2019-06-26 10:09:43.0, BEGIN_TIME=2019-06-26 10:09:43.0, ID=8C3189ED0639F220E05011AC0200107C, SIGN=1, RESULT={sayHello=hello, my name is weiweian, 123 years old., name=weiweian, age=123}, URL=/mvclab/test/testAspectJAround}
{INTFNAME=@349f84fe, END_TIME=2019-06-26 10:40:22.0, BEGIN_TIME=2019-06-26 10:40:22.0, ID=8C31F7934D601BCFE05011AC02001092, SIGN=1, RESULT={sayHello=hello, my name is weiweian, 123 years old., name=weiweian, age=123}, URL=/mvclab/test/testAspectJAround}
...

...
{ID=8C31D356D681E364E05011AC03000F08, NAME=Alex, AGE=20}
{ID=8C31D356D682E364E05011AC03000F08, NAME=An, AGE=18}
...

　　可见，intf_caller_log表中的记录和test表中的记录都能正常查询出来。查询其它表也应该是相应的数据。

　　2.发布到tomcat测试

　　分别访问controller中的测试路径，页面显示如下：

[
    {
        "INTFNAME": "@3507200d",
        "END_TIME": "26-6月 -19",
        "BEGIN_TIME": "26-6月 -19",
        "SIGN": "1",
        "RESULT": "{sayHello=hello, my name is weiweian, 123 years old., name=weiweian, age=123}",
        "URL": "/mvclab/test/testAspectJAround"
    },
    {
        "INTFNAME": "@3507200d",
        "END_TIME": "26-6月 -19",
        "BEGIN_TIME": "26-6月 -19",
        "SIGN": "1",
        "RESULT": "{sayHello=hello, my name is weiweian, 123 years old., name=weiweian, age=123}",
        "URL": "/mvclab/test/testAspectJAround"
    },
   ...

[
    {
        "ID": "8C31D356D681E364E05011AC03000F08",
        "NAME": "Alex",
        "AGE": "20"
    },
    {
        "ID": "8C31D356D682E364E05011AC03000F08",
        "NAME": "An",
        "AGE": "18"
    }
]

五、Hibernate事务管理配置多数据源

　　只修改pom.xml添加相关jar包，以及application.xml添加Hibernate事务管理，其它和上述一样不变。

　　1.pom.xml

　　添加hibernate相关jar包

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>laboratory</groupId>
  <artifactId>mvclab</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>mcv Maven Webapp</name>
  <url>http://maven.apache.org</url>
  
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <spring.version>5.1.5.RELEASE</spring.version>
        <mybatis.version>3.2.8</mybatis.version>
        <mybatis-spring.version>1.2.2</mybatis-spring.version>
        <spring-jpa-version>1.3.2.RELEASE</spring-jpa-version>
    </properties>
  
  <dependencies>
          <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!--spring-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</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-beans</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-orm</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-aspects</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-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!--日志-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

        <!--tomcat所需jar包-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.24</version>
        </dependency>
        
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>2.2.2</version>
        </dependency>
        <!-- Spring JPA dependencies -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>${spring-jpa-version}</version>
        </dependency>

        <!-- Hibernate dependencies -->
        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.4.2.Final</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.4.2.Final</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.hibernate.javax.persistence/hibernate-jpa-2.0-api -->
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency>

        <!--返回object对象所需要的依赖，它在<mvc:annotation-driven>注册时注入-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
        
        <!-- 补充 -->
        <!-- https://mvnrepository.com/artifact/aopalliance/aopalliance -->
        <dependency>
            <groupId>aopalliance</groupId>
            <artifactId>aopalliance</artifactId>
            <version>1.0</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.13</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjrt -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.8.9</version>
        </dependency>  
        
        <!-- MyBatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>${mybatis-spring.version}</version>
        </dependency>
        <!-- dbcp数据源 -->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        
        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.26</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.20</version>
            <scope>provided</scope>
        </dependency>
  </dependencies>
  <build>
    <finalName>mcv</finalName>
  </build>
</project>

　　2.applicationContext.xml

　　注释掉jdbc事务管理，添加hibernate事务管理。

<?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"  
    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/aop 
        http://www.springframework.org/schema/aop/spring-aop.xsd">

    <!-- context:设置注解扫描包注解
        注: 如果springmvc-servlet中扫描注解没有排除@Service注解，这里要设置扫描除@Controller之外的其它所有注解
     -->
    <context:component-scan base-package="com.mvc">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
        <!-- 自定义异常处理 -->
        <context:exclude-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice" />
    </context:component-scan>
    
    <!-- 开启@Autowired注解扫描
        注: 它等价于<bean class="org.springframework.beans.factory.annotation. AutowiredAnnotationBeanPostProcessor "/> 
        注: 配置了<context:component-scan />，默认包含对@Autowired的配置，因此下面这个配置就不需要了
     -->
    <context:annotation-config/>
    
    <!-- 注册数据源配置文件 -->
    <context:property-placeholder location="classpath:jdbc.properties" />
    <!-- 注册数据源对象 这里用Spring内置数据源 -->
    <bean id="dataSource1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName">
            <value>${oracle11g.driverClass}</value>
        </property>
        <property name="url">
            <value>${oracle11g.url}</value>
        </property>
        <property name="username">
            <value>${oracle11g.username}</value>
        </property>
        <property name="password">
            <value>${oracle11g.password}</value>
        </property>
        <property name="maxActive">
            <value>${oracle11g.maxActive}</value>
        </property>
        <property name="maxIdle">
            <value>${oracle11g.maxIdle}</value>
        </property>
        <property name="maxWait">
            <value>${oracle11g.maxWait}</value>
        </property>
        <property name="defaultAutoCommit">
            <value>${oracle11g.defaultAutoCommit}</value>
        </property>
        <property name="timeBetweenEvictionRunsMillis">
            <value>${oracle11g.timeBetweenEvictionRunsMillis}</value>
        </property>
        <property name="minEvictableIdleTimeMillis">
            <value>${oracle11g.minEvictableIdleTimeMillis}</value>
        </property>
    </bean>
    <bean id="dataSource2" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close">
        <property name="driverClassName">
            <value>${oracle11g-1.driverClass}</value>
        </property>
        <property name="url">
            <value>${oracle11g-1.url}</value>
        </property>
        <property name="username">
            <value>${oracle11g-1.username}</value>
        </property>
        <property name="password">
            <value>${oracle11g-1.password}</value>
        </property>
        <property name="maxActive">
            <value>${oracle11g-1.maxActive}</value>
        </property>
        <property name="maxIdle">
            <value>${oracle11g-1.maxIdle}</value>
        </property>
        <property name="maxWait">
            <value>${oracle11g-1.maxWait}</value>
        </property>
        <property name="defaultAutoCommit">
            <value>${oracle11g-1.defaultAutoCommit}</value>
        </property>
        <property name="timeBetweenEvictionRunsMillis">
            <value>${oracle11g-1.timeBetweenEvictionRunsMillis}</value>
        </property>
        <property name="minEvictableIdleTimeMillis">
            <value>${oracle11g-1.minEvictableIdleTimeMillis}</value>
        </property>
    </bean>
    <!-- 配置动态数据源 -->
    <bean id="dynamicDataSource" class="com.mvc.dynamicDataSource.DynamicDataSource">
        <property name="targetDataSources">  
              <map key-type="java.lang.String">
                  <!-- 指定lookupKey和与之对应的数据源 -->
                  <entry key="dataSource1" value-ref="dataSource1" />
                  <entry key="dataSource2" value-ref="dataSource2" />
              </map>  
          </property>  
          <!-- 指定默认的数据源 -->
          <property name="defaultTargetDataSource" ref="dataSource1" /> 
    </bean>
    
    <!-- 配置事务管理对象--> 
    <!-- 
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource1" />
    </bean>
     -->
     
    <!-- Hibernate JPA vendor adapter -->
    <bean id="hibernateJpaVendorAdapter"
          class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="databasePlatform" value="org.hibernate.dialect.Oracle10gDialect"/>
    </bean>
    <!-- JPA entity manager factory -->
    <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource1"/>
        <property name="jpaVendorAdapter" ref="hibernateJpaVendorAdapter"/>
        <property name="packagesToScan" value="com.mvc.laboratory"/>
        <property name="jpaProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
                <prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop>
                <prop key="hibernate.show_sql">false</prop>
            </props>
        </property>
    </bean>
    <!-- JPA transaction manager -->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>

    <!-- 将所有具有@Transactional注解的Bean自动配置为声明式事务支持 --> 
    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>

    <!-- MyBatis 数据源和sql- -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dynamicDataSource"/>
        <property name="mapperLocations" value="classpath:/mappings/**/*.xml"/>
        <property name="configLocation" value="classpath:/mybatis-config.xml"></property>
    </bean>
    <!-- MyBayis 扫描器配置-->
    <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.mvc.laboratory"/>
    </bean>
    
    
    <!--接收json数据-->
    <bean id="jsonHttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>application/json;charset=UTF-8</value>
            </list>
        </property>
    </bean>
    
    <!-- 配置事务自动代理 -->
    <aop:aspectj-autoproxy proxy-target-class="true" />
</beans>

　　同样进行单元测试，动态数据源切换可照常使用。