FOP it!

Question

Hi,
I am using Apache FOP tool to convert an xml file into PDF.
I have written up an xsl file.
When working from the cmd prompt I would execute the following as required by FOP
FOP --> Fop -xsl foo.xsl -xml foo.xml -pdf foo.pdf and this works fine.
The problem is when I try to get this same funtionality from within a java programme using Runtime.exec().
This is what I have so far.....
String[] env = {"cmd",
     "/c",
     "fop.bat",
"Fop",
"-xsl",
"styleSheet.xsl",
"-xml",                                   "xmlFile.xml",
"-pdf",
"outputPDF.pdf" };
Runtime rt = Runtime.getRuntime();
Process p = rt.exec(command);
When this code is executed, it either
1) Hangs and nothing happens
2) If it does execute it throws up an error:
"java' is not recognized as an internal or external command, operable program or batch file"
What I noticed were the following:
1) FOP does work when no arguements are passed, i.e it displays a list of options (similar to what you would get if you entered 'javac' at the cmd prompt without the filename.)
2) By calling FOP, I am running the fop.bat file which has the following line in it
java -cp "%LOCALCLASSPATH%" org.apache.fop.apps.Fop %1 %2 %3 %4 %5 %6 %7 %8
Once this is removed, the error is also removed - but I get no output.
Is it because my java programme is calling the batch file which is then calling java again?
Anybody experienced similar problems, or have any hints/tips or suggestions??
Any help, much appreciated.
Thank you.

Answer 1

The most common cause that a process started with exec will hang is that its output is never read.
However, is there any reason why you want to use a batch file to run FOP rather than calling it directly (http://xml.apache.org/fop/embedding.html)?