jsf - Im trying to add a logo to a pdf file but theres an error message "com.lowagie.text.Document cannot be cast to com.itextpdf.text.Document" -

i'm trying build little webtool , tried add logo pdf using preprocessor in dataexporter (primefaces). have set server logo stored.

now when try export datatable pdfi keep getting error message:

com.lowagie.text.document cannot cast com.itextpdf.text.document

thats bean contains preprocessor method

    public void preprocesspdf (object document)  throws ioexception, badelementexception, documentexception  {     document pdf = (document) document;      servletcontext servletcontext = (servletcontext) facescontext.getcurrentinstance().getexternalcontext().getcontext();      string logo = servletcontext.getrealpath("") + file.separator + "http:" + file.separator + file.separator +"192.168.1.34:8080" + file.separator     + "bilder" + file.separator + "ubs.jpg";     pdf.add(image.getinstance(logo));  } 

that xhtml file :

<h:commandbutton value="als pdf exportieren">      <!--  <h:outputtext value="als pdf exportieren" />-->            <p:dataexporter type="pdf" target="modulbewertung"         filename="zusammenfassung_modulbewertung"         preprocessor="#{handleevents.preprocesspdf}"/>  </h:commandbutton> 

com.lowagie.text.document cannot cast com.itextpdf.text.document

this error message means you're trying cast object of type com.lowagie.text.document object of type com.itextpdf.text.document, while object isn't instance of @ all. that's happening in below line:

document pdf = (document) document;  

you need make sure import declaration document below:

import com.lowagie.text.document; 

and not other one. if can't import it, verify if you're using right version of itext. make sure don't have multiple different versioned itext libraries too.

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unrelated concrete problem, should never ever use getrealpath(). rather use getresource() or getresourceasstream(). see what servletcontext.getrealpath("/") mean , when should use it. further, don't need fiddle around file.separator compose url.