@Override
    public SelectorDO findByNameAndPluginNameAndNamespaceId(final String name, final String pluginName, final String namespaceId) {
        PluginDO pluginDO = pluginMapper.selectByName(pluginName);
        return selectorMapper.findByNameAndPluginIdAndNamespaceId(name, pluginDO.getId(), namespaceId);
    }
Find selectorDO by name and plugin name and namespaceId.

@param name       the name
@param pluginName the plugin name
@param namespaceId namespaceId
@return the selector do
shenyu-admin/src/main/java/org/apache/shenyu/admin/service/impl/SelectorServiceImpl.java