tds/src/main/java/thredds/server/ncss/controller/NcssGridController.java
private void checkRequestedVars(CoverageCollection gcd, NcssGridParamsBean params)
          throws VariableNotContainedInDatasetException {

    // if var == all --> all variables requested
    if (params.getVar().get(0).equalsIgnoreCase("all")) {
      params.setVar(getAllGridNames(gcd));
      return;
    }

    // Check vars are contained in the grid
    for (String gridName : params.getVar()) {
      Coverage grid = gcd.findCoverage(gridName);
      if (grid == null)
        throw new VariableNotContainedInDatasetException(
                "Variable: " + gridName + " is not contained in the requested dataset");
    }
  }
private void checkRequestedVars(CoverageCollection gcd, NcssGridParamsBean params)
          throws VariableNotContainedInDatasetException {

    // if var == all --> all variables requested
    if (params.getVar().get(0).equalsIgnoreCase("all")) {
      params.setVar(getAllGridNames(gcd));
      return;
    }

    // Check vars are contained in the grid
    for (String gridName : params.getVar()) {
      Coverage grid = gcd.findCoverage(gridName);
      if (grid == null)
        throw new VariableNotContainedInDatasetException(
                "Variable: " + gridName + " is not contained in the requested dataset");
    }
  }
Checks that all the requested vars exist. If "all", fills out the param.vars with all grid names
Throws exception if some of the variables in the request are not contained in the dataset