[jdom-interest] quesion of EntifyRef and DocType

[ÁõΪ Golden]

Hi,all:
   I use jdom API to process my XML files,and I find it is powerful.
   Recently,I want to add some entity and dtd to my XML files,and then I have some
question about the usage of the EntityRef and DodcType classes. I look over the
javaDoc of the Jdom,but I got little information which could answer my questions.
   Are there some to give me some example program about how to use these two
classes?
   Thanks!