public static String buildDiscoveryUpstreamPath(final String namespaceId, final String pluginName, final String proxySelectorName) {
        return handlePathData(String.join(PATH_SEPARATOR, PATH_SEPARATOR + namespaceId, DISCOVERY_UPSTREAM, pluginName, proxySelectorName));
    }
buildDiscoveryUpstreamPath.

@param namespaceId       namespaceId
@param pluginName        pluginName
@param proxySelectorName selectorId
@return /namespaceId/shenyu/discoveryUpstream/pluginName/proxySelectorName
shenyu-common/src/main/java/org/apache/shenyu/common/constant/DefaultPathConstants.java