Here is rough example that works with CF9. There are probably more elegant methods, but this should give you the basic idea.
Note - IIRC CF8 uses an earlier version of iText (1.4). CF9 uses 2.1.0. So I am relatively certain it will not run "as is" with CF8. If needed, you can use the JavaLoader.cfc to run a later version.
Update: Modified to show one way of defining a specific font, size and color. The correct settings will vary depending on your system, desired font, encoding, etcetera.
<cfscript>
inputPath = "c:\sourceFile.pdf";
outputPath = "c:\sourceFileWithLink.pdf";
try {
// initialize objects
pdfReader = createObject("java", "com.lowagie.text.pdf.PdfReader").init( inputPath );
outStream = createObject("java", "java.io.FileOutputStream").init( outputPath );
pdfStamper = createObject("java", "com.lowagie.text.pdf.PdfStamper").init( pdfReader, outStream );
// create a chunk with a link to www.google.com
chunk = createObject("java", "com.lowagie.text.Chunk").init("Go To Google");
chunk.setAnchor("http://www.google.com");
//////////////////////////////////////////
// Define embedded font
BaseFont = createObject("java", "com.lowagie.text.pdf.BaseFont");
Font = createObject("java", "com.lowagie.text.Font");
bf = BaseFont.createFont("c:/windows/fonts/Framd.ttf", BaseFont.CP1252, BaseFont.EMBEDDED);
// Create the main font object (size 14)
Color = createObject("java", "java.awt.Color");
textFont = Font.init(bf, 14, Font.UNDERLINE, Color.RED);
// Apply the font to the chunk text
chunk.setFont( textFont );
//////////////////////////////////////////
// prepare to write the link onto the *first* page only
cb = pdfStamper.getOverContent(1); // first page
ct = createObject("java", "com.lowagie.text.pdf.ColumnText").init(cb);
ct.addElement( chunk );
// position towards bottom right of page
page = pdfReader.getPageSize(1);
llx = page.getRight()-200;
lly = page.getBottom();
urx = page.getRight();
ury = page.getBottom() + 36;
// initialize column dimensions
ct.setSimpleColumn(llx, lly, urx, ury);
// write the text
ct.go();
WriteOutput("Finished!");
}
finally
{
// cleanup
if (IsDefined("pdfStamper")) {
pdfStamper.close();
}
if (IsDefined("outStream")) {
outStream.close();
}
}
</cfscript>