better NPE message

ws/Docbook/Dbtools/src/main/java/de/hdm_stuttgart/mi/codeformat/Docbook2docbook.java

@@ -312,8 +312,10 @@ public class Docbook2docbook {
 				errMsg = "No unique lookup of class '" + unqualifiedClassname + "'";
 			} else {
 				final Package pack = package2name(methodComponents, 0, methodComponents.length - 2);
+                final String packageName = pack.getName();
 				methodName = methodComponents [methodComponents.length - 1];
-				final String fullyQualifiedClassName = pack.getName().concat(".").concat(methodComponents[methodComponents.length - 2]);
+				final String classname = methodComponents[methodComponents.length - 2];
+				final String fullyQualifiedClassName = packageName.concat(".").concat(classname);
 
 				uniqueClass = findClass(fullyQualifiedClassName);
 				errMsg = "Unable to find class '" + fullyQualifiedClassName + "'";