Problem with the I/O

[Sayers]

When I try and compile I get this :
Exception in thread "main" java.lang.NullPointerException
 at java.util.Hashtable.put(Hashtable.java:394)
 at java.util.Properties.setProperty(Properties.java:143)
 at xmlHandeler.XML_Add_Book.<init>(XML_Add_Book.java:18)
 at xmlHandeler.XML_Add_Book.main(XML_Add_Book.java:33)

I'm not quite sure what it is.

[Sayers (sjsayers93)]

I've found out more specifically this is an error with the pre-defined or "made on spot" values [strings] , if I declare the string when the .setProperty is working, the code makes an xml file.

[Sayers (sjsayers93)]

I was able to fix this in version 7 by ignoring this problem and changing the code, I'm going to leave the code open but set it's importance lower due to that I've "fixed" it.