public interface DataSource  extends CommonDataSource,Wrapper {/*** <p>Attempts to establish a connection with the data source that* this <code>DataSource</code> object represents.** @return  a connection to the data source* @exception SQLException if a database access error occurs*/Connection getConnection() throws SQLException;/*** <p>Attempts to establish a connection with the data source that* this <code>DataSource</code> object represents.** @param username the database user on whose behalf the connection is*  being made* @param password the user's password* @return  a connection to the data source* @exception SQLException if a database access error occurs* @since 1.4*/Connection getConnection(String username, String password)throws SQLException;}

public Connection getConnection() throws SQLException {return determineTargetDataSource().getConnection();}public Connection getConnection(String username, String password) throws SQLException {return determineTargetDataSource().getConnection(username, password);}

protected DataSource determineTargetDataSource() {Assert.notNull(this.resolvedDataSources, "DataSource router not initialized");Object lookupKey = determineCurrentLookupKey();DataSource dataSource = this.resolvedDataSources.get(lookupKey);if (dataSource == null && (this.lenientFallback || lookupKey == null)) {dataSource = this.resolvedDefaultDataSource;}if (dataSource == null) {throw new IllegalStateException("Cannot determine target DataSource for lookup key [" + lookupKey + "]");}return dataSource;}

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface DataSource {String value();
}

public class DynamicDataSource extends AbstractRoutingDataSource {@Overrideprotected Object determineCurrentLookupKey() {// TODO Auto-generated method stubreturn DynamicDataSourceHolder.getDataSouce();}}public class DynamicDataSourceHolder {public static final ThreadLocal<String> holder = new ThreadLocal<String>();public static void putDataSource(String name) {holder.set(name);}public static String getDataSouce() {return holder.get();}
}

public class DataSourceAspect {public void before(JoinPoint point){Object target = point.getTarget();String method = point.getSignature().getName();Class<?>[] classz = target.getClass().getInterfaces();Class<?>[] parameterTypes = ((MethodSignature) point.getSignature()).getMethod().getParameterTypes();try {Method m = classz[0].getMethod(method, parameterTypes);if (m != null && m.isAnnotationPresent(DataSource.class)) {DataSource data = m.getAnnotation(DataSource.class);DynamicDataSourceHolder.putDataSource(data.value());System.out.println(data.value());}} catch (Exception e) {// TODO: handle exception}}
}

<bean id="masterdataSource"class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver" /><property name="url" value="jdbc:mysql://127.0.0.1:3306/shop" /><property name="username" value="root" /><property name="password" value="yangyanping0615" /></bean><bean id="slavedataSource"class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver" /><property name="url" value="jdbc:mysql://127.0.0.1:3306/test" /><property name="username" value="root" /><property name="password" value="yangyanping0615" /></bean><beans:bean id="dataSource" class="com.air.shop.common.db.DynamicDataSource"><property name="targetDataSources">  <map key-type="java.lang.String">  <!-- write --><entry key="master" value-ref="masterdataSource"/>  <!-- read --><entry key="slave" value-ref="slavedataSource"/>  </map>  </property>  <property name="defaultTargetDataSource" ref="masterdataSource"/>  </beans:bean><bean id="transactionManager"class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource" /></bean><!-- 配置SqlSessionFactoryBean --><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource" /><property name="configLocation" value="classpath:config/mybatis-config.xml" /></bean>

<!-- 配置数据库注解aop --><aop:aspectj-autoproxy></aop:aspectj-autoproxy><beans:bean id="manyDataSourceAspect" class="com.air.shop.proxy.DataSourceAspect" /><aop:config><aop:aspect id="c" ref="manyDataSourceAspect"><aop:pointcut id="tx" expression="execution(* com.air.shop.mapper.*.*(..))"/><aop:before pointcut-ref="tx" method="before"/></aop:aspect></aop:config><!-- 配置数据库注解aop -->

public interface UserMapper {@DataSource("master")public void add(User user);@DataSource("master")public void update(User user);@DataSource("master")public void delete(int id);@DataSource("slave")public User loadbyid(int id);@DataSource("master")public User loadbyname(String name);@DataSource("slave")public List<User> list();
}