dubbo找不到dubbo.xsd报错下载

dubbo找不到dubbo.xsd报错, 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 .