[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
Map<String, String> defaultParameters = defaults == null ? null : new HashMap<String, String>(defaults);
        if (defaultParameters != null) {
            defaultParameters.remove(PROTOCOL_KEY);
            defaultParameters.remove(USERNAME_KEY);
            defaultParameters.remove(PASSWORD_KEY);
            defaultParameters.remove(HOST_KEY);
            defaultParameters.remove(PORT_KEY);
            defaultParameters.remove(PATH_KEY);
        }
        URL u = URL.valueOf(url);
        boolean changed = false;
        String protocol = u.getProtocol();
        String username = u.getUsername();
        String password = u.getPassword();
        String host = u.getHost();
        int port = u.getPort();
        String path = u.getPath();
        Map<String, String> parameters = new HashMap<String, String>(u.getParameters());
        if ((protocol == null || protocol.length() == 0) && defaultProtocol != null && defaultProtocol.length() > 0) {
            changed = true;
            protocol = defaultProtocol;
        }
        if ((username == null || username.length() == 0) && defaultUsername != null && defaultUsername.length() > 0) {
            changed = true;
            username = defaultUsername;
        }
        if ((password == null || password.length() == 0) && defaultPassword != null && defaultPassword.length() > 0) {
            changed = true;
            password = defaultPassword;
        }