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

public class ChooseDataSource extends AbstractRoutingDataSource {

	@Override

	protected Object determineCurrentLookupKey() {

		return HandleDataSource.getDataSource();

	}

}

import java.lang.annotation.ElementType;

import java.lang.annotation.Retention;

import java.lang.annotation.RetentionPolicy;

import java.lang.annotation.Target;

/**

 * RUNTIME 编译器将把注释记录在类文件中，在运行时 VM 将保留注释，因此可以反射性地读取。

 *

 * @author yangGuang

 *

 */

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.METHOD)

public @interface DataSource {

    String value();

}

import java.lang.reflect.Method;

import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.reflect.MethodSignature;

public class DataSourceAspect {

    /**

     * 拦截目标方法，获取由@DataSource指定的数据源标识，设置到线程存储中以便切换数据源

     *

     * @param point

     * @throws Exception

     */

    public void intercept(JoinPoint point) throws Exception {

        Class<?> target = point.getTarget().getClass();

        MethodSignature signature = (MethodSignature) point.getSignature();

        // 默认使用目标类型的注解，如果没有则使用其实现接口的注解

        for (Class<?> clazz : target.getInterfaces()) {

            resolveDataSource(clazz, signature.getMethod());

        }

        resolveDataSource(target, signature.getMethod());

    }

    /**

     * 提取目标对象方法注解和类型注解中的数据源标识

     *

     * @param clazz

     * @param method

     */

    private void resolveDataSource(Class<?> clazz, Method method) {

        try {

            Class<?>[] types = method.getParameterTypes();

            // 默认使用类型注解

            if (clazz.isAnnotationPresent(DataSource.class)) {

                DataSource source = clazz.getAnnotation(DataSource.class);

                HandleDataSource.putDataSource(source.value());

            }

            // 方法注解可以覆盖类型注解

            Method m = clazz.getMethod(method.getName(), types);

            if (m != null && m.isAnnotationPresent(DataSource.class)) {

                DataSource source = m.getAnnotation(DataSource.class);

                HandleDataSource.putDataSource(source.value());

            }

        } catch (Exception e) {

            // System.out.println(clazz + ":" + e.getMessage());

        }

    }

}

public class HandleDataSource {

    public static final ThreadLocal<String> holder = new ThreadLocal<String>();

    public static void putDataSource(String datasource) {

        holder.set(datasource);

    }

    public static String getDataSource() {

        return holder.get();

    }

    public static void clearDataSource() {

        holder.remove();

    }

}

<bean id="dataSource" class="hometree.ecs.business.db.dao.util.ChooseDataSource">

        <property name="targetDataSources">

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

                  <!-- write -->

                 <entry key="write" value-ref="writeDataSource"/>

                 <!-- read -->

                 <entry key="read" value-ref="readDataSource"/>

                 <!-- 读写 -->

                 <entry key="wr" value-ref="dataSourceAdmin"/>

              </map>    

        </property>

        <!-- 默认 -->

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

    </bean>

    <!-- 激活自动代理功能 -->

        <aop:aspectj-autoproxy proxy-target-class="true"/>

    <!-- 配置数据库注解aop -->

        <bean id="dataSourceAspect" class="aa.dd.cc.DataSourceAspect" />

        <aop:config>

            <aop:aspect id="c" ref="dataSourceAspect">

            <!--扫描下边的所有方法都要过before  -->

                <aop:pointcut id="tx" expression="execution(* aa.dd.cc.*.*(..))"/>

                <aop:before pointcut-ref="tx" method="intercept"/>  <!-- intercept是执行的方法 -->

            </aop:aspect>

        </aop:config>

        <!-- 配置数据库注解aop -->