legacy/src/main/java/thredds/catalog/InvDatasetImpl.java
static public String resolve(InvDataset ds, String href) {
    InvCatalog cat = ds.getParentCatalog();
    if (cat != null) {
      try {
        java.net.URI uri = cat.resolveUri(href);
        href = uri.toString();
      } catch (java.net.URISyntaxException e) {
        logger.warn("InvDatasetImpl.writeHtml: error parsing URL= " + href);
      }
    }
    return href;
  }
static public String resolve(InvDataset ds, String href) {
    InvCatalog cat = ds.getParentCatalog();
    if (cat != null) {
      try {
        java.net.URI uri = cat.resolveUri(href);
        href = uri.toString();
      } catch (java.net.URISyntaxException e) {
        logger.warn("InvDatasetImpl.writeHtml: error parsing URL= " + href);
      }
    }
    return href;
  }
resolve reletive URLS against the catalog URL.

@param ds   use ds parent catalog, if it exists
@param href URL to resolve
@return resolved URL