legacy/src/main/java/thredds/catalog/InvService.java
public boolean isRelativeBase() {
    if (getServiceType() == ServiceType.COMPOUND)
      return true;

    if (uri == null) {
      try {
        uri = new java.net.URI(base);
      } catch (java.net.URISyntaxException e) {
        throw new IllegalArgumentException(e.getMessage());
      }
    }

    return !uri.isAbsolute();
  }
public boolean isRelativeBase() {
    if (getServiceType() == ServiceType.COMPOUND)
      return true;

    if (uri == null) {
      try {
        uri = new java.net.URI(base);
      } catch (java.net.URISyntaxException e) {
        throw new IllegalArgumentException(e.getMessage());
      }
    }

    return !uri.isAbsolute();
  }
See if the service Base is reletive
@return true if the service Base is reletive