Help with a prototype

I'm having trouble creating a prototype for the following java code:
 
PdfWriter writer = PdfWriter.getInstance(document, new
FileOutputStream("/PDF/Test.pdf"));


Here's what I have so far:
D jFileOutputStream...
D                 S               O   CLASS(*JAVA
D                                     :'java.io.FileOutputStream')

D Document        S               O   CLASS(*JAVA
D                                     :'com.lowagie.text.Document')

D PdfWriter       S               O   CLASS(*JAVA
D                                     :'com.lowagie.text.pdf.PdfWriter')

D itextPdfWriterGetInstance...
D                 PR                   like(PdfWriter)
D                                      ExtProc(*JAVA:
D                                      'com.lowagie.text.pdf.PdfWriter':
D                                      'getInstance')
D   documentPdf                        LIKE(Document)
D   filename                           LIKE(jOutputStream)

D PdfDocument      S                   LIKE(Document)
D writerFile       S                   LIKE(jFileOutputStream)
D ThisWriter       S                   LIKE(PdfWriter)
 /free
  
  // Document is created without errors (PdfDocument)
  // file output stream is created without errors (writerFile)

  ThisWriter = itextPdfWriterGetInstance(ThisWriter:
                                         PdfDocument:
                                         writerFile);

 /End-free

The error I get is: java.lang.NoSuchMethodError: getInstance
I've triple checked everything and the spelling and capitalization is
correct for the prototype. 
The jar file resides at /QIBM/UserData/Java400/ext, so this shouldn't be
a classpath issue as far as I know.
Can anyone tell me if they see anything wrong?