public Resolution getUniqueValues() throws JSONException {
    JSONObject json = new JSONObject();
    json.put("success", Boolean.FALSE);

    try {
      Layer layer = applicationLayer.getService().getSingleLayer(applicationLayer.getLayerName());
      if (layer != null && layer.getFeatureType() != null) {
        SimpleFeatureType sft = layer.getFeatureType();
        List<String> beh = sft.calculateUniqueValues(attribute);
        json.put("uniqueValues", new JSONArray(beh));
        json.put("success", Boolean.TRUE);
      }
    } catch (Exception e) {
      json.put("msg", e.toString());
    }
    return new StreamingResolution("application/json", new StringReader(json.toString()));
  }
  private void makeAttributeJSONArray(final SimpleFeatureType layerSft) throws JSONException {
    List<ConfiguredAttribute> cas = applicationLayer.getAttributes();
    // Sort the attributes, by featuretype and the featuretyp
    Collections.sort(
        cas,
        new Comparator<ConfiguredAttribute>() {
          @Override
          public int compare(ConfiguredAttribute o1, ConfiguredAttribute o2) {
            if (o1.getFeatureType() == null) {
              return -1;
            }
            if (o2.getFeatureType() == null) {
              return 1;
            }
            if (o1.getFeatureType().getId().equals(layerSft.getId())) {
              return -1;
            }
            if (o2.getFeatureType().getId().equals(layerSft.getId())) {
              return 1;
            }
            return o1.getFeatureType().getId().compareTo(o2.getFeatureType().getId());
          }
        });
    for (ConfiguredAttribute ca : cas) {
      JSONObject j = ca.toJSONObject();

      // Copy alias over from feature type
      SimpleFeatureType sft = ca.getFeatureType();
      if (sft == null) {
        sft = layerSft;
      }
      AttributeDescriptor ad = sft.getAttribute(ca.getAttributeName());
      j.put("alias", ad.getAlias());
      j.put("featureTypeAttribute", ad.toJSONObject());

      attributesJSON.put(j);
    }
  }
  private List<String> rebuildAttributes(SimpleFeatureType sft) {
    Layer layer = applicationLayer.getService().getSingleLayer(applicationLayer.getLayerName());
    List<String> attributesToRetain = new ArrayList<String>();
    for (AttributeDescriptor ad : sft.getAttributes()) {
      String name = ad.getName();

      String fullName = sft.getId() + ":" + name;
      // if attribute already added return.
      if (attributesToRetain.contains(fullName)) {
        return attributesToRetain;
      }
      attributesToRetain.add(fullName);

      // Used for display in JSP
      if (StringUtils.isNotBlank(ad.getAlias())) {
        attributeAliases.put(fullName, ad.getAlias());
      }

      if (applicationLayer.getAttribute(sft, name) == null) {
        ConfiguredAttribute ca = new ConfiguredAttribute();
        // default visible if not geometry type
        // and not a attribute of a related featuretype
        boolean defaultVisible = true;
        if (layer.getFeatureType().getId() != sft.getId()
            || AttributeDescriptor.GEOMETRY_TYPES.contains(ad.getType())) {
          defaultVisible = false;
        }
        ca.setVisible(defaultVisible);
        ca.setAttributeName(name);
        ca.setFeatureType(sft);
        applicationLayer.getAttributes().add(ca);
        Stripersist.getEntityManager().persist(ca);

        if (!"save".equals(getContext().getEventName())) {
          String message = "Nieuw attribuut \"{0}\" gevonden in ";
          if (layer.getFeatureType().getId() != sft.getId()) {
            message += "gekoppelde ";
          }
          message += "attribuutbron";
          if (layer.getFeatureType().getId() == sft.getId()) {
            message += ": wordt zichtbaar na opslaan";
          }
          getContext().getMessages().add(new SimpleMessage(message, name));
        }
      }
    }
    if (sft.getRelations() != null) {
      for (FeatureTypeRelation rel : sft.getRelations()) {
        attributesToRetain.addAll(rebuildAttributes(rel.getForeignFeatureType()));
      }
    }
    return attributesToRetain;
  }
  @Before
  public void synchronizeFeatureTypeAndLoadInfo() throws JSONException {

    Layer layer = applicationLayer.getService().getSingleLayer(applicationLayer.getLayerName());
    if (layer == null) {
      getContext()
          .getValidationErrors()
          .addGlobalError(
              new SimpleError(
                  "Laag niet gevonden bij originele service - verwijder deze laag uit niveau"));
      return;
    }

    for (StyleLibrary sld : layer.getService().getStyleLibraries()) {
      Map style = new HashMap();
      JSONObject styleTitleJson = new JSONObject();

      style.put("id", "sld:" + sld.getId());
      style.put(
          "title", "SLD stijl: " + sld.getTitle() + (sld.isDefaultStyle() ? " (standaard)" : ""));

      // Find stuff for layerName
      if (sld.getNamedLayerUserStylesJson() != null) {
        JSONObject sldNamedLayerJson = new JSONObject(sld.getNamedLayerUserStylesJson());
        if (sldNamedLayerJson.has(layer.getName())) {
          JSONObject namedLayer = sldNamedLayerJson.getJSONObject(layer.getName());
          if (namedLayer.has("title")) {
            styleTitleJson.put("namedLayerTitle", namedLayer.get("title"));
          }
          JSONArray userStyles = namedLayer.getJSONArray("styles");
          if (userStyles.length() > 0) {
            JSONObject userStyle = userStyles.getJSONObject(0);
            if (userStyle.has("title")) {
              styleTitleJson.put("styleTitle", userStyle.get("title"));
            }
          }
        }
      }
      styles.add(style);
      stylesTitleJson.put((String) style.get("id"), styleTitleJson);
    }
    if (layer.getDetails().containsKey(Layer.DETAIL_WMS_STYLES)) {
      JSONArray wmsStyles =
          new JSONArray(layer.getDetails().get(Layer.DETAIL_WMS_STYLES).getValue());
      for (int i = 0; i < wmsStyles.length(); i++) {
        JSONObject wmsStyle = wmsStyles.getJSONObject(i);
        Map style = new HashMap();
        style.put("id", "wms:" + wmsStyle.getString("name"));
        style.put(
            "title",
            "WMS server stijl: "
                + wmsStyle.getString("name")
                + " ("
                + wmsStyle.getString("title")
                + ")");
        JSONObject styleTitleJson = new JSONObject();
        styleTitleJson.put("styleTitle", wmsStyle.getString("title"));
        styles.add(style);
        stylesTitleJson.put((String) style.get("id"), styleTitleJson);
      }
    }
    if (!styles.isEmpty()) {
      List<Map> temp = new ArrayList();
      Map s = new HashMap();
      s.put("id", "registry_default");
      s.put("title", "In gegevensregister als standaard ingestelde SLD");
      temp.add(s);
      s = new HashMap();
      s.put("id", "none");
      s.put("title", "Geen: standaard stijl van WMS service zelf");
      temp.add(s);
      temp.addAll(styles);
      styles = temp;
    }

    // Synchronize configured attributes with layer feature type

    if (layer.getFeatureType() == null || layer.getFeatureType().getAttributes().isEmpty()) {
      applicationLayer.getAttributes().clear();
    } else {
      List<String> attributesToRetain = new ArrayList();

      SimpleFeatureType sft = layer.getFeatureType();
      editable = sft.isWriteable();
      // Rebuild ApplicationLayer.attributes according to Layer FeatureType
      // New attributes are added at the end of the list; the original
      // order is only used when the Application.attributes list is empty
      // So a feature for reordering attributes per applicationLayer is
      // possible.
      // New Attributes from a join or related featureType are added at the
      // end of the list.
      attributesToRetain = rebuildAttributes(sft);

      // JSON info about attributed required for editing
      makeAttributeJSONArray(layer.getFeatureType());
      // Remove ConfiguredAttributes which are no longer present
      List<ConfiguredAttribute> attributesToRemove = new ArrayList();
      for (ConfiguredAttribute ca : applicationLayer.getAttributes()) {
        if (ca.getFeatureType() == null) {
          ca.setFeatureType(layer.getFeatureType());
        }
        if (!attributesToRetain.contains(ca.getFullName())) {
          // Do not modify list we are iterating over
          attributesToRemove.add(ca);
          if (!"save".equals(getContext().getEventName())) {
            getContext()
                .getMessages()
                .add(
                    new SimpleMessage(
                        "Attribuut \"{0}\" niet meer beschikbaar in attribuutbron: wordt verwijderd na opslaan",
                        ca.getAttributeName()));
          }
        }
      }
      for (ConfiguredAttribute ca : attributesToRemove) {
        applicationLayer.getAttributes().remove(ca);
        Stripersist.getEntityManager().remove(ca);
      }
    }
  }