MetadataService logs error msg when using generic implementation.

[chickenlj]

[23/07/19 05:30:24:024 CST] main ERROR integration.MetadataReportService: [DUBBO] publishProvider getServiceDescriptor error. providerUrl: dubbo://30.5.121.125:20880/org.apache.dubbo.samples.generic.call.api.HelloService?anyhost=true&application=generic-impl-provider&deprecated=false&dubbo=2.0.2&dynamic=true&generic=true&interface=org.apache.dubbo.samples.generic.call.api.HelloService&methods=*&register=true&release=2.7.3&side=provider, dubbo version: 2.7.3, current host: 30.5.121.125
java.lang.ClassNotFoundException: org.apache.dubbo.samples.generic.call.api.HelloService
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.dubbo.metadata.integration.MetadataReportService.publishProvider(MetadataReportService.java:97)
at org.apache.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:623)
at org.apache.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:457)
at org.apache.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:415)
at org.apache.dubbo.config.ServiceConfig.export(ServiceConfig.java:378)
at org.apache.dubbo.samples.generic.call.GenericImplProvider.main(GenericImplProvider.java:48)

Reproduce by running dubbo-samples-generic-impl

[chickenlj]

https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-generic/dubbo-samples-generic-impl/dubbo-samples-generic-impl-provider/src/main/java/org/apache/dubbo/samples/generic/call

[cvictory]

I will check this issue.