配置dubbo服务xml后，程序能正常执行，但validate会出现一些异常：
Multiple annotations found at this line:
- cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'dubbo:application'.
- schema_reference.4: Failed to read schema document 'http://code.alibabatech.com/schema/dubbo/dubbo.xsd',
because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not
<xsd:schema>
解决办法：
1）下载dubbo的jar包，比如：dubbo-2.5.3.jar，解压能获取到dubbo.xsd
2）在eclipse中导入文件dubbo.xsd:
windows->preferrence->xml->xmlcatalog,
add->catalog entry ->file system 选择文件dubbo.xsd
添加后，Key默认是这样的：http://code.alibabatech.com/schema/dubbo
3）修改key值为：
http://code.alibabatech.com/schema/dubbo/dubbo.xsd，因为xml配置文件中xsi:schemaLocation的也是这个值，保持一致，重新validate，异常消失
fuck 我也不知道这是为什么
