public void doGetDAS(ReqState rs) throws Exception {
    HttpServletResponse response = rs.getResponse();

    GuardedDataset ds = null;
    try {
      ds = getDataset(rs);
      if (ds == null) return;

      response.setContentType("text/plain");
      response.setHeader("XDODS-Server", getServerVersion());
      response.setHeader("Content-Description", "dods-das");

      OutputStream Out = new BufferedOutputStream(response.getOutputStream());

      DAS myDAS = ds.getDAS();
      myDAS.print(Out);

    } finally { // release lock if needed
      if (ds != null) ds.release();
    }
  }
  public void doGetHTML(ReqState rs) throws Exception {
    HttpServletResponse response = rs.getResponse();
    HttpServletRequest request = rs.getRequest();
    GuardedDataset ds = null;
    try {
      ds = getDataset(rs);
      if (ds == null) return;

      response.setHeader("XDODS-Server", getServerVersion());
      response.setContentType("text/html");
      response.setHeader("Content-Description", "dods-form");

      // Utilize the getDDS() method to get	a parsed and populated DDS
      // for this server.
      ServerDDS myDDS = ds.getDDS();
      DAS das = ds.getDAS();
      GetHTMLInterfaceHandler2 di = new GetHTMLInterfaceHandler2();
      di.sendDataRequestForm(request, response, rs.getDataSet(), myDDS, das);

    } finally { // release lock if needed
      if (ds != null) ds.release();
    }
  }
  public void doGetDDX(ReqState rs) throws Exception {
    HttpServletResponse response = rs.getResponse();

    GuardedDataset ds = null;
    try {
      ds = getDataset(rs);
      if (null == ds) return;

      response.setContentType("text/plain");
      response.setHeader("XDODS-Server", getServerVersion());
      response.setHeader("Content-Description", "dods-ddx");

      OutputStream out = new BufferedOutputStream(response.getOutputStream());

      ServerDDS myDDS = ds.getDDS();
      myDDS.ingestDAS(ds.getDAS());

      if (rs.getConstraintExpression().equals("")) { // No Constraint Expression?
        // Send the whole DDS
        myDDS.printXML(out);
        out.flush();
      } else { // Otherwise, send the constrained DDS

        // Instantiate the CEEvaluator and parse the constraint expression
        CEEvaluator ce = new CEEvaluator(myDDS);
        ce.parseConstraint(rs);

        // Send the constrained DDS back to the client
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(out));
        myDDS.printConstrainedXML(pw);
        pw.flush();
      }

    } finally { // release lock if needed
      if (ds != null) ds.release();
    }
  }