Add readNullableStartTag method.

src/fr/devinsy/util/xml/XMLReader.java

@@ -121,9 +121,9 @@ public class XMLReader
 		// Load next event.
 		if (this.nextEvent == null)
 		{
-			if (in.hasNext())
+			if (this.in.hasNext())
 			{
-				this.nextEvent = in.nextEvent();
+				this.nextEvent = this.in.nextEvent();
 			}
 		}
 
@@ -275,6 +275,39 @@ public class XMLReader
 		return result;
 	}
 
+	/**
+	 * 
+	 * @param label
+	 * @return
+	 * @throws XMLStreamException
+	 * @throws XMLBadFormatException
+	 * @throws Exception
+	 */
+	public XMLTag readNullableStartTag(final String label) throws XMLStreamException, XMLBadFormatException
+	{
+		XMLTag result;
+
+		//
+		result = readTag();
+
+		//
+		if (result == null)
+		{
+			throw new XMLBadFormatException("XML file ends prematurely, start tag [" + label + "] is expected.");
+		}
+		else if ((result.getType() != TagType.START) && (result.getType() != TagType.EMPTY))
+		{
+			throw new XMLBadFormatException("Start tag [" + label + "] is missing.");
+		}
+		else if (!StringUtils.equals(result.getLabel(), label))
+		{
+			throw new XMLBadFormatException("Tag with label [" + label + "] is missing.");
+		}
+
+		//
+		return result;
+	}
+
 	/**
 	 * 
 	 * @param label
@@ -345,9 +378,9 @@ public class XMLReader
 				event = this.nextEvent;
 				this.nextEvent = null;
 			}
-			else if (in.hasNext())
+			else if (this.in.hasNext())
 			{
-				event = in.nextEvent();
+				event = this.in.nextEvent();
 			}
 			else
 			{