diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/AbstractWidgetRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/AbstractWidgetRenderer.java
index 52503ca3e9..4c0b9de94e 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/AbstractWidgetRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/AbstractWidgetRenderer.java
@@ -23,7 +23,6 @@
 
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringEscapeUtils;
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.core.i18n.I18nUtil;
@@ -95,22 +94,21 @@ public ItemUIRegistry getItemUIRegistry() {
      */
     protected String preprocessSnippet(String originalSnippet, Widget w) {
         String snippet = originalSnippet;
-        snippet = StringUtils.replace(snippet, "%widget_id%", itemUIRegistry.getWidgetId(w));
-        snippet = StringUtils.replace(snippet, "%icon_type%", ICON_TYPE);
-        snippet = StringUtils.replace(snippet, "%item%", w.getItem() != null ? w.getItem() : "");
+        snippet = snippet.replace("%widget_id%", itemUIRegistry.getWidgetId(w));
+        snippet = snippet.replace("%icon_type%", ICON_TYPE);
+        snippet = snippet.replace("%item%", w.getItem() != null ? w.getItem() : "");
         // Optimization: avoid calling 3 times itemUIRegistry.getLabel(w)
         String text = itemUIRegistry.getLabel(w);
-        snippet = StringUtils.replace(snippet, "%label%", getLabel(text));
-        snippet = StringUtils.replace(snippet, "%value%", getValue(text));
-        snippet = StringUtils.replace(snippet, "%has_value%", Boolean.valueOf(hasValue(text)).toString());
-        snippet = StringUtils.replace(snippet, "%visibility_class%",
-                itemUIRegistry.getVisiblity(w) ? "" : "mdl-form__row--hidden");
+        snippet = snippet.replace("%label%", getLabel(text));
+        snippet = snippet.replace("%value%", getValue(text));
+        snippet = snippet.replace("%has_value%", Boolean.valueOf(hasValue(text)).toString());
+        snippet = snippet.replace("%visibility_class%", itemUIRegistry.getVisiblity(w) ? "" : "mdl-form__row--hidden");
 
         String state = getState(w);
-        snippet = StringUtils.replace(snippet, "%state%", escapeURL(state));
+        snippet = snippet.replace("%state%", escapeURL(state));
 
         String category = getCategory(w);
-        snippet = StringUtils.replace(snippet, "%category%", escapeURL(category));
+        snippet = snippet.replace("%category%", escapeURL(category));
 
         return snippet;
     }
@@ -263,7 +261,7 @@ protected String processColor(Widget w, String originalSnippet) {
         if (color != null) {
             style = "style=\"color:" + color + "\"";
         }
-        snippet = StringUtils.replace(snippet, "%labelstyle%", style);
+        snippet = snippet.replace("%labelstyle%", style);
 
         style = "";
         color = itemUIRegistry.getValueColor(w);
@@ -271,7 +269,7 @@ protected String processColor(Widget w, String originalSnippet) {
         if (color != null) {
             style = "style=\"color:" + color + "\"";
         }
-        snippet = StringUtils.replace(snippet, "%valuestyle%", style);
+        snippet = snippet.replace("%valuestyle%", style);
 
         return snippet;
     }
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ChartRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ChartRenderer.java
index 2fd6389565..6fba28247d 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ChartRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ChartRenderer.java
@@ -14,7 +14,6 @@
 
 import java.util.Date;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -115,16 +114,16 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
             snippet = preprocessSnippet(snippet, w);
 
             if (chart.getRefresh() > 0) {
-                snippet = StringUtils.replace(snippet, "%update_interval%", Integer.toString(chart.getRefresh()));
+                snippet = snippet.replace("%update_interval%", Integer.toString(chart.getRefresh()));
             } else {
-                snippet = StringUtils.replace(snippet, "%update_interval%", "0");
+                snippet = snippet.replace("%update_interval%", "0");
             }
 
-            snippet = StringUtils.replace(snippet, "%id%", itemUIRegistry.getWidgetId(w));
-            snippet = StringUtils.replace(snippet, "%proxied_url%", chartUrl);
-            snippet = StringUtils.replace(snippet, "%valid_url%", "true");
-            snippet = StringUtils.replace(snippet, "%ignore_refresh%", ignoreRefresh ? "true" : "false");
-            snippet = StringUtils.replace(snippet, "%url%", url);
+            snippet = snippet.replace("%id%", itemUIRegistry.getWidgetId(w));
+            snippet = snippet.replace("%proxied_url%", chartUrl);
+            snippet = snippet.replace("%valid_url%", "true");
+            snippet = snippet.replace("%ignore_refresh%", ignoreRefresh ? "true" : "false");
+            snippet = snippet.replace("%url%", url);
 
             sb.append(snippet);
         } catch (ItemNotFoundException e) {
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ColorpickerRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ColorpickerRenderer.java
index 3831d41bdd..ef84f5b6fc 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ColorpickerRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ColorpickerRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -80,27 +79,29 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         }
 
         // Should be called before preprocessSnippet
-        snippet = StringUtils.replace(snippet, "%state%", hexValue);
-        snippet = StringUtils.replace(snippet, "%icon_state%", escapeURL(hexValue));
+        snippet = snippet.replace("%state%", hexValue);
+        snippet = snippet.replace("%icon_state%", escapeURL(hexValue));
 
         snippet = preprocessSnippet(snippet, w);
-        snippet = StringUtils.replace(snippet, "%purelabel%", purelabel);
-        snippet = StringUtils.replace(snippet, "%frequency%", frequency);
-        snippet = StringUtils.replace(snippet, "%servletname%", WebAppServlet.SERVLET_NAME);
+        if (purelabel != null) {
+            snippet = snippet.replace("%purelabel%", purelabel);
+        }
+        snippet = snippet.replace("%frequency%", frequency);
+        snippet = snippet.replace("%servletname%", WebAppServlet.SERVLET_NAME);
 
         String style = "";
         String color = itemUIRegistry.getLabelColor(w);
         if (color != null) {
             style = "color:" + color;
         }
-        snippet = StringUtils.replace(snippet, "%labelstyle%", style);
+        snippet = snippet.replace("%labelstyle%", style);
 
         style = "";
         color = itemUIRegistry.getValueColor(w);
         if (color != null) {
             style = "color:" + color;
         }
-        snippet = StringUtils.replace(snippet, "%valuestyle%", style);
+        snippet = snippet.replace("%valuestyle%", style);
 
         sb.append(snippet);
         return ECollections.emptyEList();
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/FrameRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/FrameRenderer.java
index 2def9f9c72..a8b1af1d4a 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/FrameRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/FrameRenderer.java
@@ -16,7 +16,6 @@
 import java.util.List;
 
 import org.apache.commons.lang.StringEscapeUtils;
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.i18n.LocaleProvider;
@@ -59,8 +58,8 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         String label = StringEscapeUtils.escapeHtml(itemUIRegistry.getLabel(w));
         List<String> frameClassList = new ArrayList<>();
 
-        snippet = StringUtils.replace(snippet, "%label%", label);
-        snippet = StringUtils.replace(snippet, "%widget_id%", itemUIRegistry.getWidgetId(w));
+        snippet = snippet.replace("%label%", label);
+        snippet = snippet.replace("%widget_id%", itemUIRegistry.getWidgetId(w));
 
         if (label.isEmpty()) {
             frameClassList.add("mdl-form--no-label");
@@ -70,8 +69,8 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
             frameClassList.add("mdl-form--hidden");
         }
 
-        String frameClass = StringUtils.join(frameClassList, ' ');
-        snippet = StringUtils.replace(snippet, "%frame_class%", frameClass);
+        String frameClass = String.join(" ", frameClassList);
+        snippet = snippet.replace("%frame_class%", frameClass);
 
         // Process the color tags
         snippet = processColor(w, snippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/GroupRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/GroupRenderer.java
index 5ef887c487..9fc1df0c56 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/GroupRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/GroupRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -55,7 +54,7 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         String snippet = getSnippet("group");
 
         snippet = preprocessSnippet(snippet, w);
-        snippet = StringUtils.replace(snippet, "%id%", itemUIRegistry.getWidgetId(w));
+        snippet = snippet.replace("%id%", itemUIRegistry.getWidgetId(w));
 
         // Process the color tags
         snippet = processColor(w, snippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ImageRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ImageRenderer.java
index cb4745b441..59b79d9ee3 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ImageRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ImageRenderer.java
@@ -14,7 +14,6 @@
 
 import java.util.Date;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -63,13 +62,13 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         String snippet = (image.getChildren().size() > 0) ? getSnippet("image_link") : getSnippet("image");
 
         if (image.getRefresh() > 0) {
-            snippet = StringUtils.replace(snippet, "%update_interval%", Integer.toString(image.getRefresh()));
+            snippet = snippet.replace("%update_interval%", Integer.toString(image.getRefresh()));
         } else {
-            snippet = StringUtils.replace(snippet, "%update_interval%", "0");
+            snippet = snippet.replace("%update_interval%", "0");
         }
 
         String widgetId = itemUIRegistry.getWidgetId(w);
-        snippet = StringUtils.replace(snippet, "%id%", widgetId);
+        snippet = snippet.replace("%id%", widgetId);
         snippet = preprocessSnippet(snippet, w);
 
         boolean validUrl = isValidURL(image.getUrl());
@@ -90,10 +89,10 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
             url = URL_NONE_ICON;
             ignoreRefresh = true;
         }
-        snippet = StringUtils.replace(snippet, "%valid_url%", validUrl ? "true" : "false");
-        snippet = StringUtils.replace(snippet, "%proxied_url%", proxiedUrl);
-        snippet = StringUtils.replace(snippet, "%ignore_refresh%", ignoreRefresh ? "true" : "false");
-        snippet = StringUtils.replace(snippet, "%url%", url);
+        snippet = snippet.replace("%valid_url%", validUrl ? "true" : "false");
+        snippet = snippet.replace("%proxied_url%", proxiedUrl);
+        snippet = snippet.replace("%ignore_refresh%", ignoreRefresh ? "true" : "false");
+        snippet = snippet.replace("%url%", url);
 
         sb.append(snippet);
         return ECollections.emptyEList();
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ListRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ListRenderer.java
index b477cb1107..08d71a120f 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ListRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/ListRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -63,11 +62,11 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
 
         if (state != null) {
             for (String row : state.toString().split(((List) w).getSeparator())) {
-                rowSB.append(StringUtils.replace(rowSnippet, "%title%", escapeHtml(row)));
+                rowSB.append(rowSnippet.replace("%title%", escapeHtml(row)));
             }
         }
 
-        snippet = StringUtils.replace(snippet, "%rows%", rowSB.toString());
+        snippet = snippet.replace("%rows%", rowSB.toString());
 
         // Process the color tags
         snippet = processColor(w, snippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/MapviewRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/MapviewRenderer.java
index 4a5f118c9f..193b9a6b6a 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/MapviewRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/MapviewRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -67,26 +66,26 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
             PointType pointState = (PointType) state;
             double latitude = pointState.getLatitude().doubleValue();
             double longitude = pointState.getLongitude().doubleValue();
-            snippet = StringUtils.replace(snippet, "%url%", MAP_URL);
-            snippet = StringUtils.replace(snippet, "%lat%", Double.toString(latitude));
-            snippet = StringUtils.replace(snippet, "%lon%", Double.toString(longitude));
-            snippet = StringUtils.replace(snippet, "%lonminus%", Double.toString(longitude - MAP_ZOOM));
-            snippet = StringUtils.replace(snippet, "%lonplus%", Double.toString(longitude + MAP_ZOOM));
-            snippet = StringUtils.replace(snippet, "%latminus%", Double.toString(latitude - MAP_ZOOM));
-            snippet = StringUtils.replace(snippet, "%latplus%", Double.toString(latitude + MAP_ZOOM));
+            snippet = snippet.replace("%url%", MAP_URL);
+            snippet = snippet.replace("%lat%", Double.toString(latitude));
+            snippet = snippet.replace("%lon%", Double.toString(longitude));
+            snippet = snippet.replace("%lonminus%", Double.toString(longitude - MAP_ZOOM));
+            snippet = snippet.replace("%lonplus%", Double.toString(longitude + MAP_ZOOM));
+            snippet = snippet.replace("%latminus%", Double.toString(latitude - MAP_ZOOM));
+            snippet = snippet.replace("%latplus%", Double.toString(latitude + MAP_ZOOM));
         } else {
-            snippet = StringUtils.replace(snippet, "%url%", "images/map-marker-off.png");
+            snippet = snippet.replace("%url%", "images/map-marker-off.png");
         }
 
-        snippet = StringUtils.replace(snippet, "%map_url%", MAP_URL);
-        snippet = StringUtils.replace(snippet, "%map_zoom%", Double.toString(MAP_ZOOM));
+        snippet = snippet.replace("%map_url%", MAP_URL);
+        snippet = snippet.replace("%map_zoom%", Double.toString(MAP_ZOOM));
 
         int height = mapview.getHeight();
         if (height == 0) {
             height = 4; // set default height to something viewable
         }
         height = height * 36;
-        snippet = StringUtils.replace(snippet, "%height%", Integer.toString(height));
+        snippet = snippet.replace("%height%", Integer.toString(height));
 
         sb.append(snippet);
         return ECollections.emptyEList();
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/PageRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/PageRenderer.java
index de0c5f08bc..0cf4b2fba2 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/PageRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/PageRenderer.java
@@ -17,7 +17,6 @@
 import java.util.List;
 import java.util.Set;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.EObject;
@@ -109,12 +108,12 @@ public StringBuilder processPage(String id, String sitemap, String label, EList<
         if (labelPlain.contains("[") && labelPlain.endsWith("]")) {
             labelPlain = labelPlain.replace("[", "").replace("]", "");
         }
-        snippet = StringUtils.replace(snippet, "%label%", escapeHtml(labelPlain));
-        snippet = StringUtils.replace(snippet, "%servletname%", WebAppServlet.SERVLET_NAME);
-        snippet = StringUtils.replace(snippet, "%sitemap%", sitemap);
-        snippet = StringUtils.replace(snippet, "%htmlclass%", config.getCssClassList());
-        snippet = StringUtils.replace(snippet, "%icon_type%", ICON_TYPE);
-        snippet = StringUtils.replace(snippet, "%theme%", config.getTheme());
+        snippet = snippet.replace("%label%", escapeHtml(labelPlain));
+        snippet = snippet.replace("%servletname%", WebAppServlet.SERVLET_NAME);
+        snippet = snippet.replace("%sitemap%", sitemap);
+        snippet = snippet.replace("%htmlclass%", config.getCssClassList());
+        snippet = snippet.replace("%icon_type%", ICON_TYPE);
+        snippet = snippet.replace("%theme%", config.getTheme());
 
         String[] parts = snippet.split("%children%");
 
@@ -139,9 +138,9 @@ private void processChildren(StringBuilder sb_pre, StringBuilder sb_post, EList<
             if (!(firstChild instanceof Frame || parent instanceof Frame || parent instanceof Sitemap
                     || parent instanceof org.openhab.core.model.sitemap.sitemap.List)) {
                 String frameSnippet = getSnippet("frame");
-                frameSnippet = StringUtils.replace(frameSnippet, "%widget_id%", "");
-                frameSnippet = StringUtils.replace(frameSnippet, "%label%", "");
-                frameSnippet = StringUtils.replace(frameSnippet, "%frame_class%", "mdl-form--no-label");
+                frameSnippet = frameSnippet.replace("%widget_id%", "");
+                frameSnippet = frameSnippet.replace("%label%", "");
+                frameSnippet = frameSnippet.replace("%frame_class%", "mdl-form--no-label");
 
                 String[] parts = frameSnippet.split("%children%");
                 if (parts.length > 1) {
@@ -230,26 +229,33 @@ public CharSequence renderSitemapList(Set<SitemapProvider> sitemapProviders) thr
         StringBuilder sb = new StringBuilder();
         if (sitemapList.isEmpty()) {
             String listEmptySnippet = getSnippet("sitemaps_list_empty");
-            listEmptySnippet = StringUtils.replace(listEmptySnippet, "%sitemaps-list-empty.info%",
-                    localizeText("@text/sitemaps-list-empty.info"));
+            String text = localizeText("@text/sitemaps-list-empty.info");
+            if (text != null) {
+                listEmptySnippet = listEmptySnippet.replace("%sitemaps-list-empty.info%", text);
+            }
             sb.append(listEmptySnippet);
         } else {
             for (String sitemap : sitemapList) {
-                sb.append(StringUtils.replace(sitemapSnippet, "%sitemap%", sitemap));
+                sb.append(sitemapSnippet.replace("%sitemap%", sitemap));
             }
         }
 
-        listSnippet = StringUtils.replace(listSnippet, "%sitemaps-list.welcome%",
-                localizeText("@text/sitemaps-list.welcome"));
-        listSnippet = StringUtils.replace(listSnippet, "%sitemaps-list.available-sitemaps%",
-                localizeText("@text/sitemaps-list.available-sitemaps"));
-        listSnippet = StringUtils.replace(listSnippet, "%items%", sb.toString());
+        String text = localizeText("@text/sitemaps-list.welcome");
+        if (text != null) {
+            listSnippet = listSnippet.replace("%sitemaps-list.welcome%", text);
+        }
+
+        text = localizeText("@text/sitemaps-list.available-sitemaps");
+        if (text != null) {
+            listSnippet = listSnippet.replace("%sitemaps-list.available-sitemaps%", text);
+        }
+
+        listSnippet = listSnippet.replace("%items%", sb.toString());
 
-        pageSnippet = StringUtils.replace(pageSnippet, "%title%", "BasicUI");
-        pageSnippet = StringUtils.replace(pageSnippet, "%htmlclass%",
-                config.getCssClassList() + " page-welcome-sitemaps");
-        pageSnippet = StringUtils.replace(pageSnippet, "%theme%", config.getTheme());
-        pageSnippet = StringUtils.replace(pageSnippet, "%content%", listSnippet);
+        pageSnippet = pageSnippet.replace("%title%", "BasicUI");
+        pageSnippet = pageSnippet.replace("%htmlclass%", config.getCssClassList() + " page-welcome-sitemaps");
+        pageSnippet = pageSnippet.replace("%theme%", config.getTheme());
+        pageSnippet = pageSnippet.replace("%content%", listSnippet);
 
         return pageSnippet;
     }
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SelectionRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SelectionRenderer.java
index b5cbc80c6d..817657c6f8 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SelectionRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SelectionRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -106,10 +105,10 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
                 }
             }
         }
-        snippet = StringUtils.replace(snippet, "%rows%", rowSB.toString());
-        snippet = StringUtils.replace(snippet, "%value_map%", escapeHtml(jsonObject.toString()));
-        snippet = StringUtils.replace(snippet, "%label_header%", getLabel(w));
-        snippet = StringUtils.replace(snippet, "%value_header%", mappingLabel != null ? mappingLabel : getValue(w));
+        snippet = snippet.replace("%rows%", rowSB.toString());
+        snippet = snippet.replace("%value_map%", escapeHtml(jsonObject.toString()));
+        snippet = snippet.replace("%label_header%", getLabel(w));
+        snippet = snippet.replace("%value_header%", mappingLabel != null ? mappingLabel : getValue(w));
 
         // Process the color tags
         snippet = processColor(w, snippet);
@@ -128,13 +127,15 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
 
         if (item instanceof NumberItem && ((NumberItem) item).getDimension() != null) {
             String unit = getUnitForWidget(w);
-            command = StringUtils.replace(command, UnitUtils.UNIT_PLACEHOLDER, unit);
-            label = StringUtils.replace(label, UnitUtils.UNIT_PLACEHOLDER, unit);
+            if (unit != null) {
+                command = command.replace(UnitUtils.UNIT_PLACEHOLDER, unit);
+                label = label.replace(UnitUtils.UNIT_PLACEHOLDER, unit);
+            }
         }
 
-        rowSnippet = StringUtils.replace(rowSnippet, "%item%", w.getItem() != null ? w.getItem() : "");
-        rowSnippet = StringUtils.replace(rowSnippet, "%cmd%", escapeHtml(command));
-        rowSnippet = StringUtils.replace(rowSnippet, "%label%", escapeHtml(label));
+        rowSnippet = rowSnippet.replace("%item%", w.getItem() != null ? w.getItem() : "");
+        rowSnippet = rowSnippet.replace("%cmd%", escapeHtml(command));
+        rowSnippet = rowSnippet.replace("%label%", escapeHtml(label));
 
         State compareMappingState = state;
         if (state instanceof QuantityType) { // convert the item state to the command value for proper
@@ -144,9 +145,9 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
 
         if (compareMappingState != null && compareMappingState.toString().equals(command)) {
             mappingLabel = label;
-            rowSnippet = StringUtils.replace(rowSnippet, "%checked%", "checked=\"true\"");
+            rowSnippet = rowSnippet.replace("%checked%", "checked=\"true\"");
         } else {
-            rowSnippet = StringUtils.replace(rowSnippet, "%checked%", "");
+            rowSnippet = rowSnippet.replace("%checked%", "");
         }
 
         rowSB.append(rowSnippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SetpointRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SetpointRenderer.java
index df49ec014d..81f8987d7b 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SetpointRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SetpointRenderer.java
@@ -14,7 +14,6 @@
 
 import java.math.BigDecimal;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -75,11 +74,13 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         String snippet = getSnippet("setpoint");
 
         snippet = preprocessSnippet(snippet, w);
-        snippet = StringUtils.replace(snippet, "%value%", getValue(w));
-        snippet = StringUtils.replace(snippet, "%minValue%", minValue.toString());
-        snippet = StringUtils.replace(snippet, "%maxValue%", maxValue.toString());
-        snippet = StringUtils.replace(snippet, "%step%", step.toString());
-        snippet = StringUtils.replace(snippet, "%unit%", unit);
+        snippet = snippet.replace("%value%", getValue(w));
+        snippet = snippet.replace("%minValue%", minValue.toString());
+        snippet = snippet.replace("%maxValue%", maxValue.toString());
+        snippet = snippet.replace("%step%", step.toString());
+        if (unit != null) {
+            snippet = snippet.replace("%unit%", unit);
+        }
 
         // Process the color tags
         snippet = processColor(w, snippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SliderRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SliderRenderer.java
index ae13dd6027..8910858765 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SliderRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SliderRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -68,12 +67,14 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         String unit = getUnitForWidget(w);
 
         snippet = preprocessSnippet(snippet, w);
-        snippet = StringUtils.replace(snippet, "%frequency%", frequency);
-        snippet = StringUtils.replace(snippet, "%switch%", s.isSwitchEnabled() ? "1" : "0");
-        snippet = StringUtils.replace(snippet, "%unit%", unit);
-        snippet = StringUtils.replace(snippet, "%minValue%", minValueOf(s));
-        snippet = StringUtils.replace(snippet, "%maxValue%", maxValueOf(s));
-        snippet = StringUtils.replace(snippet, "%step%", stepOf(s));
+        snippet = snippet.replace("%frequency%", frequency);
+        snippet = snippet.replace("%switch%", s.isSwitchEnabled() ? "1" : "0");
+        if (unit != null) {
+            snippet = snippet.replace("%unit%", unit);
+        }
+        snippet = snippet.replace("%minValue%", minValueOf(s));
+        snippet = snippet.replace("%maxValue%", maxValueOf(s));
+        snippet = snippet.replace("%step%", stepOf(s));
 
         // Process the color tags
         snippet = processColor(w, snippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SwitchRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SwitchRenderer.java
index 39f2b95739..4ff5abc3a5 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SwitchRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/SwitchRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -136,8 +135,8 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
                     buildButton(s, mapping.getLabel(), mapping.getCmd(), -1, nbButtons > 1, item, state, buttons);
                 }
             }
-            snippet = StringUtils.replace(snippet, "%buttons%", buttons.toString());
-            snippet = StringUtils.replace(snippet, "%count%", Integer.toString(nbButtons));
+            snippet = snippet.replace("%buttons%", buttons.toString());
+            snippet = snippet.replace("%count%", Integer.toString(nbButtons));
         }
 
         // Process the color tags
@@ -156,17 +155,19 @@ private void buildButton(Switch w, @Nullable String lab, String cmd, int maxLabe
 
         if (item instanceof NumberItem && ((NumberItem) item).getDimension() != null) {
             String unit = getUnitForWidget(w);
-            command = StringUtils.replace(command, UnitUtils.UNIT_PLACEHOLDER, unit);
-            label = StringUtils.replace(label, UnitUtils.UNIT_PLACEHOLDER, unit);
+            if (unit != null) {
+                command = command.replace(UnitUtils.UNIT_PLACEHOLDER, unit);
+                label = label.replace(UnitUtils.UNIT_PLACEHOLDER, unit);
+            }
         }
 
         if (maxLabelSize >= 1 && label.length() > maxLabelSize) {
             label = label.substring(0, maxLabelSize - 1) + ELLIPSIS;
         }
 
-        button = StringUtils.replace(button, "%item%", w.getItem());
-        button = StringUtils.replace(button, "%cmd%", escapeHtml(command));
-        button = StringUtils.replace(button, "%label%", escapeHtml(label));
+        button = button.replace("%item%", w.getItem());
+        button = button.replace("%cmd%", escapeHtml(command));
+        button = button.replace("%label%", escapeHtml(label));
 
         String buttonClass;
         State compareMappingState = state;
@@ -180,7 +181,7 @@ private void buildButton(Switch w, @Nullable String lab, String cmd, int maxLabe
         } else {
             buttonClass = "mdl-button";
         }
-        button = StringUtils.replace(button, "%class%", buttonClass);
+        button = button.replace("%class%", buttonClass);
 
         buttons.append(button);
     }
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/TextRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/TextRenderer.java
index 63415a1aa7..0e14fccbe3 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/TextRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/TextRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -56,7 +55,7 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         String snippet = (text.getChildren().size() > 0) ? getSnippet("text_link") : getSnippet("text");
 
         snippet = preprocessSnippet(snippet, w);
-        snippet = StringUtils.replace(snippet, "%id%", itemUIRegistry.getWidgetId(w));
+        snippet = snippet.replace("%id%", itemUIRegistry.getWidgetId(w));
 
         // Process the color tags
         snippet = processColor(w, snippet);
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/VideoRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/VideoRenderer.java
index 28b14a1f24..3af05490fb 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/VideoRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/VideoRenderer.java
@@ -14,7 +14,6 @@
 
 import java.util.Date;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -81,11 +80,11 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
             } else {
                 url = URL_NONE_ICON;
             }
-            snippet = StringUtils.replace(snippet, "%valid_url%", validUrl ? "true" : "false");
-            snippet = StringUtils.replace(snippet, "%proxied_url%", proxiedUrl);
-            snippet = StringUtils.replace(snippet, "%update_interval%", "0");
-            snippet = StringUtils.replace(snippet, "%ignore_refresh%", "true");
-            snippet = StringUtils.replace(snippet, "%url%", url);
+            snippet = snippet.replace("%valid_url%", validUrl ? "true" : "false");
+            snippet = snippet.replace("%proxied_url%", proxiedUrl);
+            snippet = snippet.replace("%update_interval%", "0");
+            snippet = snippet.replace("%ignore_refresh%", "true");
+            snippet = snippet.replace("%url%", url);
         } else {
             String mediaType;
             if (videoWidget.getEncoding() != null && videoWidget.getEncoding().toLowerCase().contains("hls")) {
@@ -96,8 +95,8 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
                 url = "../proxy?sitemap=" + sitemap + "&widgetId=" + widgetId;
                 mediaType = "";
             }
-            snippet = StringUtils.replace(snippet, "%url%", url);
-            snippet = StringUtils.replace(snippet, "%media_type%", mediaType);
+            snippet = snippet.replace("%url%", url);
+            snippet = snippet.replace("%media_type%", mediaType);
         }
         sb.append(snippet);
         return ECollections.emptyEList();
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/WebviewRenderer.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/WebviewRenderer.java
index 93f4acc31f..deeb2cd56c 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/WebviewRenderer.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/render/WebviewRenderer.java
@@ -12,7 +12,6 @@
  */
 package org.openhab.ui.basic.internal.render;
 
-import org.apache.commons.lang.StringUtils;
 import org.eclipse.emf.common.util.ECollections;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -57,14 +56,14 @@ public EList<Widget> renderWidget(Widget w, StringBuilder sb, String sitemap) th
         // Process the color tags
         snippet = processColor(w, snippet);
 
-        snippet = StringUtils.replace(snippet, "%url%", webview.getUrl());
+        snippet = snippet.replace("%url%", webview.getUrl());
 
         int height = webview.getHeight();
         if (height == 0) {
             height = 4; // set default height to something viewable
         }
         height = height * 36;
-        snippet = StringUtils.replace(snippet, "%height%", Integer.toString(height));
+        snippet = snippet.replace("%height%", Integer.toString(height));
 
         sb.append(snippet);
         return ECollections.emptyEList();
diff --git a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/servlet/CmdServlet.java b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/servlet/CmdServlet.java
index b9fbb07c30..d5293352cb 100644
--- a/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/servlet/CmdServlet.java
+++ b/bundles/org.openhab.ui.basic/src/main/java/org/openhab/ui/basic/internal/servlet/CmdServlet.java
@@ -87,11 +87,12 @@ protected void service(@NonNullByDefault({}) HttpServletRequest req, @NonNullByD
                     // we need a special treatment for the "TOGGLE" command of switches;
                     // this is no command officially supported and must be translated
                     // into real commands by the webapp.
-                    if ((item instanceof SwitchItem || item instanceof GroupItem) && commandName.equals("TOGGLE")) {
+                    if ((item instanceof SwitchItem || item instanceof GroupItem) && "TOGGLE".equals(commandName)) {
                         commandName = OnOffType.ON.equals(item.getStateAs(OnOffType.class)) ? "OFF" : "ON";
                     }
 
-                    Command command = TypeParser.parseCommand(item.getAcceptedCommandTypes(), commandName);
+                    Command command = commandName == null ? null
+                            : TypeParser.parseCommand(item.getAcceptedCommandTypes(), commandName);
                     if (command != null) {
                         eventPublisher.post(ItemEventFactory.createCommandEvent(itemName, command));
                     } else {
diff --git a/bundles/org.openhab.ui.cometvisu/src/main/java/org/openhab/ui/cometvisu/internal/StateBeanMessageBodyWriter.java b/bundles/org.openhab.ui.cometvisu/src/main/java/org/openhab/ui/cometvisu/internal/StateBeanMessageBodyWriter.java
index cf1fb7d2f8..022be01353 100644
--- a/bundles/org.openhab.ui.cometvisu/src/main/java/org/openhab/ui/cometvisu/internal/StateBeanMessageBodyWriter.java
+++ b/bundles/org.openhab.ui.cometvisu/src/main/java/org/openhab/ui/cometvisu/internal/StateBeanMessageBodyWriter.java
@@ -27,7 +27,6 @@
 import javax.ws.rs.ext.MessageBodyWriter;
 import javax.ws.rs.ext.Provider;
 
-import org.apache.commons.lang.StringUtils;
 import org.openhab.ui.cometvisu.internal.backend.model.StateBean;
 
 /**
@@ -83,7 +82,7 @@ public String serialize(Object bean) {
                 }
             }
             if (states.size() > 0) {
-                msg += StringUtils.join(states, ",");
+                msg += String.join(",", states);
             }
         }
         msg += "}}";