Use StringBuilder in internal HTMLUtil class

Change-Id: I69a1496374d558f800c20c2df9e3fad8b5f7386c
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>
diff --git a/org.eclipse.ui.intro/src/org/eclipse/ui/internal/intro/impl/html/HTMLUtil.java b/org.eclipse.ui.intro/src/org/eclipse/ui/internal/intro/impl/html/HTMLUtil.java
index c508be4..e6b1df8 100644
--- a/org.eclipse.ui.intro/src/org/eclipse/ui/internal/intro/impl/html/HTMLUtil.java
+++ b/org.eclipse.ui.intro/src/org/eclipse/ui/internal/intro/impl/html/HTMLUtil.java
@@ -35,9 +35,9 @@
 	 *            false otherwise
 	 * @return
 	 */
-	public static StringBuffer createHTMLStartTag(String elementName,
+	public static StringBuilder createHTMLStartTag(String elementName,
 			Map elementAttributes, boolean insertLineBreak) {
-		StringBuffer element = new StringBuffer();
+		StringBuilder element = new StringBuilder();
 		if (elementName != null) {
 			// open the start tag
 			element.append(openHTMLStartTag(elementName));
@@ -60,7 +60,7 @@
 	 *            true to insert a new line after the start tag
 	 * @return
 	 */
-	public static StringBuffer createHTMLStartTag(String elementName,
+	public static StringBuilder createHTMLStartTag(String elementName,
 			boolean insertLineBreak) {
 		return createHTMLStartTag(elementName, null, insertLineBreak);
 	}
@@ -73,7 +73,7 @@
 	 *            the name of the element to create
 	 * @return
 	 */
-	public static StringBuffer createHTMLStartTag(String elementName) {
+	public static StringBuilder createHTMLStartTag(String elementName) {
 		return createHTMLStartTag(elementName, null, true);
 	}
 
@@ -86,9 +86,9 @@
 	 *            true to add a new line at the end
 	 * @return
 	 */
-	public static StringBuffer createHTMLEndTag(String elementName,
+	public static StringBuilder createHTMLEndTag(String elementName,
 			boolean addNewLine) {
-		StringBuffer closingElement = new StringBuffer();
+		StringBuilder closingElement = new StringBuilder();
 		if (elementName != null)
 			closingElement.append(IIntroHTMLConstants.LT).append(
 					IIntroHTMLConstants.FORWARD_SLASH).append(elementName)