Replace iterators with enhanced for loops (#10018)

This change also includes some other minor cleanup.

3 files changed, 4 insertions, 8 deletions

diff --git a/server/src/main/java/com/vaadin/server/ComponentSizeValidator.java b/server/src/main/java/com/vaadin/server/ComponentSizeValidator.java
index 19ece940e2..9e1134efed 100644
--- a/server/src/main/java/com/vaadin/server/ComponentSizeValidator.java
+++ b/server/src/main/java/com/vaadin/server/ComponentSizeValidator.java
@@ -92,9 +92,7 @@ public class ComponentSizeValidator implements Serializable {
             }
         } else if (isForm(component)) {
             HasComponents form = (HasComponents) component;
-            for (Iterator<Component> iterator = form.iterator(); iterator
-                    .hasNext();) {
-                Component child = iterator.next();
+            for (Component child : form) {
                 errors = validateComponentRelativeSizes(child, errors, parent);
             }
         }
@@ -129,7 +127,7 @@ public class ComponentSizeValidator implements Serializable {
         StringBuffer err = new StringBuffer();
         err.append("Vaadin DEBUG\n");
 
-        StringBuilder indent = new StringBuilder("");
+        StringBuilder indent = new StringBuilder();
         ComponentInfo ci;
         if (attributes != null) {
             while (attributes.size() > LAYERS_SHOWN) {
diff --git a/server/src/main/java/com/vaadin/server/JsonPaintTarget.java b/server/src/main/java/com/vaadin/server/JsonPaintTarget.java
index f7669ef135..a2df4203c8 100644
--- a/server/src/main/java/com/vaadin/server/JsonPaintTarget.java
+++ b/server/src/main/java/com/vaadin/server/JsonPaintTarget.java
@@ -224,7 +224,7 @@ public class JsonPaintTarget implements PaintTarget {
      */
     static StringBuilder escapeXML(StringBuilder xml) {
         if (xml == null || xml.length() <= 0) {
-            return new StringBuilder("");
+            return new StringBuilder();
         }
 
         final StringBuilder result = new StringBuilder(xml.length() * 2);
diff --git a/server/src/main/java/com/vaadin/ui/Upload.java b/server/src/main/java/com/vaadin/ui/Upload.java
index 27029f20de..4c6e49cd24 100644
--- a/server/src/main/java/com/vaadin/ui/Upload.java
+++ b/server/src/main/java/com/vaadin/ui/Upload.java
@@ -841,9 +841,7 @@ public class Upload extends AbstractComponent
         // this is implemented differently than other listeners to maintain
         // backwards compatibility
         if (progressListeners != null) {
-            for (Iterator<ProgressListener> it = progressListeners
-                    .iterator(); it.hasNext();) {
-                ProgressListener l = it.next();
+            for (ProgressListener l : progressListeners) {
                 l.updateProgress(totalBytes, contentLength);
             }
         }