RE: Using Xalan Transformer with FOP Driver problem
Try this. // --- // 1. Get a Source for XML document // --- // a) from string Source strSource = new StreamSource(new StringReader(xmlData)); // --- // 2. Get stylesheet transformer // --- // from file, see above examples for other types of XSL input //TransformerFactory TransformerFactory transformerFactory = TransformerFactory.newInstance (); Templates template = transformerFactory.newTemplates( new StreamSource( xslLayout )); // note - template object is multi-threaded and should be cached if you // plan to use the same XSL repeatedly Transformer transformer = template.newTransformer(); // --- // 3. Create FOP driver and set rendering mode and output stream // --- Driver driver = new Driver(); driver.setRenderer(driver.RENDER_PDF); ByteArrayOutputStream baos = new ByteArrayOutputStream (); driver.setOutputStream( baos); // initialize logger - see sample code on FOP website driver.setLogger(setLogger()); // --- // 4. Create SAXResult based on FOP Driver content handler // which will accept SAX events and build FOP tree // --- Result saxResult = new SAXResult( driver.getContentHandler() ); // 5. Use the Transformer to transform an XML Source and // send the output to a Result object. Implicitely it will // create the FOP tree by firing SAX events. transformer.transform( strSource, saxResult ); // 6. Your user is already viewing the PDF! response.getOutputStream().flush(); response.getOutputStream().close(); -Original Message- From: Anil R. Pinto [mailto:[EMAIL PROTECTED] Sent: June 21, 2002 1:35 PM To: '[EMAIL PROTECTED]' Subject: Using Xalan Transformer with FOP Driver problem Hi, I have been using FOP to create PDF files for sometime now. Mostly as embedded code within my Struts Action classes, as mentioned in http://xml.apache.org/fop/embedding.html and it has been working just fine. But this method requires the xml source to exist only as a java.io.File (if I am not mistaken), with no provision as an in memory object - like a Java String or Stream for example. So when I looked at the Xalan site and this mailing list I saw the in memory implementation possible with the TransformerFactory and Transformer classes in Xalan. So, I tried this with a simple xml and xsl to test the concept first. But, I seem to be getting the error building formatting object tree building formatting object tree javax.xml.transform.TransformerException at org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerIm pl.java:1212) at org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:2894) at java.lang.Thread.run(Thread.java:484) - java.lang.NullPointerException at org.apache.fop.fo.FOTreeBuilder.startDocument(FOTreeBuilder.java:167) at org.apache.xalan.transformer.QueuedStartDocument.flush(QueuedStartDocume nt.java:108) at org.apache.xalan.transformer.ResultTreeHandler.flushPending(ResultTreeHa ndler.java:758) at org.apache.xalan.transformer.ResultTreeHandler.startElement(ResultTreeHa ndler.java:245) at org.apache.xalan.transformer.ResultTreeHandler.startElement(ResultTreeHa ndler.java:209) at org.apache.xalan.templates.ElemLiteralResult.execute(ElemLiteralResult.j ava:704) at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(Trans formerImpl.java:2154) at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(Trans formerImpl.java:2097) at org.apache.xalan.transformer.TransformerImpl.applyTemplateToNode(Transfo rmerImpl.java:2029) at org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerIm pl.java:1189) at org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:2894) at java.lang.Thread.run(Thread.java:484) javax.xml.transform.TransformerException at org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerIm pl.java:1212) at org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:2894) at java.lang.Thread.run(Thread.java:484) - java.lang.NullPointerException at org.apache.fop.fo.FOTreeBuilder.startDocument(FOTreeBuilder.java:167) at org.apache.xalan.transformer.QueuedStartDocument.flush(QueuedStartDocume nt.java:108) at org.apache.xalan.transformer.ResultTreeHandler.flushPending(ResultTreeHa ndler.java:758) at org.apache.xalan.transformer.ResultTreeHandler.startElement(ResultTreeHa ndler.java:245) at org.apache.xalan.transformer.ResultTreeHandler.startElement(R esultTreeHandler.java:209) at org.apache.xalan.templates.ElemLiteralResult.execute(ElemLiteralResult.j ava:704) at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(Trans formerImpl.java:2154) at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(Trans
Re: Using Xalan Transformer with FOP Driver problem
I use 0.20.1 also with SAX events. I had to add this to get rid of the null pointer: //Hack fix for FOP bug. Might be unnecessary in FOP 0.20.3. StreamRenderer x = new StreamRenderer(outputStream, pdfDriver.getRenderer()); ((FOTreeBuilder)pdfDriver.getContentHandler ()).setStreamRenderer(x); Hope this helps, -Ryan
RE: Using Xalan Transformer with FOP Driver problem
Thanks Ryan, it works now !!!
In fact when you said that this problem was not there in FOP 0.20.3 I tried
that first :-) and it worked. Once I knew it did I went ahead to experiment
with FOP 0.20.1
And the fix you suggested worked.
So the code, just for reference (to others who may need it at a later time)
is
import java.io.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
import javax.xml.transform.sax.*;
import org.apache.fop.apps.Driver;
import org.apache.fop.apps.StreamRenderer;
import org.apache.fop.fo.FOTreeBuilder;
public class TestXml {
public static void main(String[] args) {
try {
// XML Will eventually be a Java String or Stream from another
source.
StreamSource xmlsource = new StreamSource(new
FileReader(simple.xml));
Driver driver =new Driver();
FileOutputStream fos = new FileOutputStream(simple.pdf);
driver.setOutputStream(fos);
driver.setRenderer(Driver.RENDER_PDF);
// Fix : ADDED this code as suggested by Ryan to work with FOP
0.20.1
(yeah, not required by FOP 0.20.3)
StreamRenderer x = new StreamRenderer(fos,
driver.getRenderer());
((FOTreeBuilder)
driver.getContentHandler()).setStreamRenderer(x);
// Fix ends
Transformer transformer =
TransformerFactory.newInstance().newTransformer(new StreamSource(new
FileReader(simple.xsl)));
// Previously threw error without above 2 line Fix
transformer.transform(xmlsource, new
SAXResult(driver.getContentHandler()));
//For test purposes only
//transformer.transform(xmlsource, new
StreamResult(System.out));
} catch (Exception e) {
e.printStackTrace();
}
}
}
Ryan, Mehmood I really appreciate your help guys. It did help.
Anil.
-Original Message-
From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]
Sent: Friday, June 21, 2002 2:56 PM
To: [EMAIL PROTECTED]
Subject:Re: Using Xalan Transformer with FOP Driver problem
I use 0.20.1 also with SAX events. I had to add this to get rid of the
null pointer:
//Hack fix for FOP bug. Might be unnecessary in FOP 0.20.3.
StreamRenderer x = new StreamRenderer(outputStream,
pdfDriver.getRenderer());
((FOTreeBuilder)pdfDriver.getContentHandler
()).setStreamRenderer(x);
Hope this helps,
-Ryan
