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
