how to CHECK if a Font is embeddable

I am using itext to create PDf documents. Certain fonts cannot be used due to licensing restrictions.

...
ExceptionConverter: com.lowagie.text.DocumentException: C:\WINDOWS\Fonts\LucidaSansRegular.ttf cannot be embedded due to licensing restrictions.
    at com.lowagie.text.pdf.TrueTypeFontUnicode.<init>(Unknown Source)
    at com.lowagie.text.pdf.BaseFont.createFont(Unknown Source)
    at com.lowagie.text.pdf.BaseFont.createFont(Unknown Source)
    at com.lowagie.text.pdf.BaseFont.createFont(Unknown Source)
   开发者_如何转开发 at com.lowagie.text.pdf.DefaultFontMapper.awtToPdf(Unknown Source)
    at com.lowagie.text.pdf.PdfGraphics2D.getCachedBaseFont(Unknown Source)
    at com.lowagie.text.pdf.PdfGraphics2D.setFont(Unknown Source)
...

I am thinking of checking font or PDF content to check this case. How to check if a Font is embeddable using java or itext?

As far as I can tell there is no direct way to identify whether a font can be embedded. I did a quick search and I don't think it is possible other than using the exception catch method as mentioned by Erik in the comments.

 // 1) have a list of all fonts ArrayList allAvailableFonts;
 // 2) second list of fonts that that can be embedded ArrayList embedableFonts;

//Iterate through every available font in allAvailableFonts

for( .... allAvailableFonts ..... )
{
   boolean isFontEmbeddable = true;
   try
   {
          // try to embed the font
   }
   catch( DocumentException de)
   {
        //this font cannot be embedded
        isEmbeddable = false;
   } 

   if( isEmbeddable )
   {
       // add to list of embeddable fonts
       embedableFonts.add ( font );
   }
}

You can probably go really hardcore and execute native calls to Windows Apis to get the same result, but I think its too much work for a simple task as this.

Did some research and found out how this exception is thrown by Java

The code which generates the above exception can be found here. http://kickjava.com/src/com/lowagie/text/pdf/TrueTypeFont.java.htm Line number 367,368

if (!justNames && embedded && os_2.fsType == 2)
     throw new DocumentException(fileName + style + " cannot be embedded due to licensing restrictions.");

The interesting part to note is the condition os_2.fsType == 2

os_2 is an instance of WindowsMetrics see line 174 here http://kickjava.com/src/com/lowagie/text/pdf/TrueTypeFont.java.htm

A search for WindowsMetrics in Google and this was what I got.

This explains that the parameter fsType holds information whether font can be embedded. http://www.microsoft.com/typography/otspec/os2ver3.htm#fst

The java equivalent of WindowsMetrics as used in itext http://www.docjar.org/docs/api/com/lowagie/text/pdf/TrueTypeFont.WindowsMetrics.html