Argh... my stoopid mistake. The servlet is a maven project, and when I bumped the fop-pdf-images version I bumped the pdfbox dependency all the way up to 1.8.5. It took digging through the source to discover that PDDocument.close() now sets everything to null - the cause of the NPE.
Rebuilt with version 1.3.1 and am testing. BTW, having a POM file in with the binary distro would be very handy for idiots like me ;) Matt On 26 June 2014 13:36, Matt Kynaston <m...@claritum.com> wrote: > Hi, > > I am embedding fop-1.1 and fop-pdf-images-2.1.0 in a tomcat servlet and > I'm experiencing a NullPointerException in PreloaderPDF.loadPDF(..). The > servlet is pretty much exactly the example servlet from the fop source, > tweaked to handle posting FO documents. > > The problem seems similar to the one discussed down towards the bottom of > http://apache-fop.1065347.n5.nabble.com/Fop-1-1-fop-pdf-images-PDFBox-1-8-3-4-td39965.html. > This suggests the problem is with the FopFactory being shared between > threads. > > However, my problem only surfaces after the server has been running for a > while - it works during testing one day and next morning throws the error > consistently. I haven't managed to create a set of steps to reproduce the > problem on demand. > > I'm no expert, so sorry if I'm being a bit dense... but the solution would > be to create a new FopFactory for every request? That seems to defeat the > purpose of the factory a bit. Is there any other workaround? > > Environment: I'm seeing this both on OSX, Java 1.7.0_25-b15 / Tomcat > 7.0.54 and CentOS6, Java 1.6.0_30 / Tomcat 6.0.24. > > Stack trace: > > java.lang.NullPointerException > > org.apache.fop.render.pdf.pdfbox.PreloaderPDF.loadPDF(PreloaderPDF.java:117) > > org.apache.fop.render.pdf.pdfbox.PreloaderPDF.preloadImage(PreloaderPDF.java:83) > > org.apache.xmlgraphics.image.loader.ImageManager.preloadImage(ImageManager.java:175) > > org.apache.xmlgraphics.image.loader.cache.ImageCache.needImageInfo(ImageCache.java:128) > > org.apache.xmlgraphics.image.loader.ImageManager.getImageInfo(ImageManager.java:122) > org.apache.fop.fo.flow.ExternalGraphic.bind(ExternalGraphic.java:81) > org.apache.fop.fo.FObj.processNode(FObj.java:124) > > org.apache.fop.fo.FOTreeBuilder$MainFOHandler.startElement(FOTreeBuilder.java:280) > org.apache.fop.fo.FOTreeBuilder.startElement(FOTreeBuilder.java:175) > > org.apache.xalan.transformer.TransformerIdentityImpl.startElement(TransformerIdentityImpl.java:1020) > > com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:506) > > com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:182) > > com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:353) > > com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2717) > > com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607) > > com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:116) > > com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:489) > > com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:835) > > com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764) > > com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123) > > com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1210) > > org.apache.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:432) > com.claritum.fop.Servlet.render(Servlet.java:315) > com.claritum.fop.Servlet.renderFOString(Servlet.java:254) > com.claritum.fop.Servlet.doPost(Servlet.java:149) > javax.servlet.http.HttpServlet.service(HttpServlet.java:646) > javax.servlet.http.HttpServlet.service(HttpServlet.java:727) > org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) > > Many thanks for any hints you can give. > > Matt > > > >
