我们当前的开发环境包括带有 ORDS 21.x、Weblogic 应用服务器和 Oracle 19c 的 Oracle APEX 21.1 版本。我们已将 Apache FOP 2.6 Web 应用程序 (fop.war) 的定制版本安装到应用程序服务器上，以使用外部打印服务器功能打印 PDF 报告。不幸的是，当我们尝试测试样本报告时，它会引发 JAVA 错误。
报告设置：
Java错误：
javax.servlet.ServletException: javax.xml.transform.TransformerException: java.lang.NullPointerException
at org.apache.fop.servlet.FopServlet.doPost(FopServlet.java:151)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:286)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:260)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:137)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:350)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at oracle.security.jps.ee.http.JpsAbsFilter$3.run(JpsAbsFilter.java:172)
at java.security.AccessController.doPrivileged(Native Method)
at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:315)
at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:650)
at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:110)
at oracle.security.jps.ee.http.JpsAbsFilter.doFilterInternal(JpsAbsFilter.java:273)
at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:147)
at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:94)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at oracle.dms.servlet.DMSServletFilter.doFilter(DMSServletFilter.java:248)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3706)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3672)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:328)
at weblogic.security.service.SecurityManager.runAsForUserCode(SecurityManager.java:197)
at weblogic.servlet.provider.WlsSecurityProvider.runAsForUserCode(WlsSecurityProvider.java:203)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:71)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2443)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2291)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2269)
at weblogic.servlet.internal.ServletRequestImpl.runInternal(ServletRequestImpl.java:1705)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1665)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:272)
at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:352)
at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:337)
at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:57)
at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)
at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:652)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:420)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:360)
Caused by: javax.xml.transform.TransformerException: java.lang.NullPointerException
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:737)
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:343)
at org.apache.fop.servlet.FopServlet.render(FopServlet.java:255)
at org.apache.fop.servlet.FopServlet.renderXML(FopServlet.java:222)
at org.apache.fop.servlet.FopServlet.doPost(FopServlet.java:142)
... 38 more
Caused by: java.lang.NullPointerException
at java.io.FilterInputStream.markSupported(FilterInputStream.java:243)
at org.apache.xmlgraphics.image.loader.util.ImageUtil.decorateMarkSupported(ImageUtil.java:213)
at org.apache.xmlgraphics.image.loader.util.ImageUtil.autoDecorateInputStream(ImageUtil.java:228)
at org.apache.xmlgraphics.image.loader.impl.AbstractImageSessionContext.createImageSource(AbstractImageSessionContext.java:378)
at org.apache.xmlgraphics.image.loader.impl.AbstractImageSessionContext.access$100(AbstractImageSessionContext.java:54)
at org.apache.xmlgraphics.image.loader.impl.AbstractImageSessionContext$UnrestrictedFallbackResolver.createSource(AbstractImageSessionContext.java:369)
at org.apache.xmlgraphics.image.loader.impl.AbstractImageSessionContext.newSource(AbstractImageSessionContext.java:95)
at org.apache.xmlgraphics.image.loader.impl.AbstractImageSessionContext.needSource(AbstractImageSessionContext.java:196)
at org.apache.xmlgraphics.image.loader.cache.ImageCache.needImageInfo(ImageCache.java:122)
at org.apache.xmlgraphics.image.loader.ImageManager.getImageInfo(ImageManager.java:123)
at org.apache.fop.fo.flow.ExternalGraphic.bind(ExternalGraphic.java:81)
at org.apache.fop.fo.FObj.processNode(FObj.java:131)
at org.apache.fop.fo.FOTreeBuilder$MainFOHandler.startElement(FOTreeBuilder.java:293)
at org.apache.fop.fo.FOTreeBuilder.startElement(FOTreeBuilder.java:179)
at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.closeStartTag(ToXMLSAXHandler.java:206)
at com.sun.org.apache.xml.internal.serializer.ToSAXHandler.flushPending(ToSAXHandler.java:283)
at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.endElement(ToXMLSAXHandler.java:245)
at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.endElement(ToXMLSAXHandler.java:557)
at GregorSamsa.template$dot$0()
at GregorSamsa.applyTemplates()
at GregorSamsa.transform()
at com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet.transform(AbstractTranslet.java:619)
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:730)
参考：