多数据源注解及实现

注解：

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

实现：

@Aspect
@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class DataSourceAspect {
    protected Logger logger = LoggerFactory.getLogger(getClass());

    @Pointcut("@annotation(io.renren.commons.dynamic.datasource.annotation.DataSource) " +
            "|| @within(io.renren.commons.dynamic.datasource.annotation.DataSource)")
    public void dataSourcePointCut() {

    }

    @Around("dataSourcePointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Class targetClass = point.getTarget().getClass();
        Method method = signature.getMethod();

        DataSource targetDataSource = (DataSource)targetClass.getAnnotation(DataSource.class);
        DataSource methodDataSource = method.getAnnotation(DataSource.class);
        if(targetDataSource != null || methodDataSource != null){
            String value;
            if(methodDataSource != null){
                value = methodDataSource.value();
            }else {
                value = targetDataSource.value();
            }

            DynamicContextHolder.push(value);
            logger.debug("set datasource is {}", value);
        }

        try {
            return point.proceed();
        } finally {
            DynamicContextHolder.poll();
            logger.debug("clean datasource");
        }
    }
}