fixed export related bugs

src/main/java/de/tudresden/inf/st/pnml/splitter/export/PnmlExporter.java

@@ -51,7 +51,7 @@ public class PnmlExporter {
         try {
             File myObj = new File(targetPath);
             if (myObj.createNewFile()) {
-                logger.info("File created: " + myObj.getName());
+                // logger.info("File created: " + myObj.getName());
             } else {
                 logger.info("File already exists.");
             }

src/main/java/de/tudresden/inf/st/pnml/splitter/export/PrimitiveElementsConverter.java

@@ -9,25 +9,27 @@ public class PrimitiveElementsConverter {
 
     private static StringBuffer clipToolSpecificsFormattedXmlBuffer(String toolName, String toolVersion, StringBuffer formattedXmlBuffer) {
 
-        if (formattedXmlBuffer != null && formattedXmlBuffer.indexOf("</toolspecific>") > -1) {
+        StringBuffer bufferCopy = new StringBuffer(formattedXmlBuffer);
+
+        if (bufferCopy != null && bufferCopy.indexOf("</toolspecific>") > -1) {
 
             int endCharsLength = 15;
             int toolNameLenth = (toolName == null) ? 0 : toolName.length();
             int toolVersionLength = (toolVersion == null) ? 0 : toolVersion.length();
             int indexGt = 0;
 
-            if (formattedXmlBuffer.indexOf("?xml") > -1) {
-                indexGt = formattedXmlBuffer.indexOf(">", formattedXmlBuffer.indexOf(">") + 1);
+            if (bufferCopy.indexOf("?xml") > -1) {
+                indexGt = bufferCopy.indexOf(">", bufferCopy.indexOf(">") + 1);
             } else {
-                indexGt = formattedXmlBuffer.indexOf(">");
+                indexGt = bufferCopy.indexOf(">");
             }
 
             if (toolNameLenth > 0 || toolVersionLength > 0) {
-                formattedXmlBuffer.delete(0, indexGt + 1);
-                formattedXmlBuffer.delete(formattedXmlBuffer.length() - endCharsLength, formattedXmlBuffer.length());
+                bufferCopy.delete(0, indexGt + 1);
+                bufferCopy.delete(bufferCopy.length() - endCharsLength, bufferCopy.length());
             }
         }
-        return formattedXmlBuffer;
+        return bufferCopy;
     }
 
     public static RefTransitionHLAPI convertRefTransitionToPnmlObject(RefTransition refTransition, TransitionHLAPI referencedTransition, RefTransitionHLAPI referencedRefTransition){