问题
I'm in the process of migrating embedded tomcat application from 7.0.59 to tomcat 8.0.20
After updating the Tomcat version when I'm starting the embedded server and try to access the home page I'm getting a NullPOinterException
ERROR {org.apache.catalina.core.ApplicationDispatcher} - Servlet.service() for servlet bridgeservlet threw exception
java.lang.NullPointerException
at org.apache.jasper.JspCompilationContext.getTldResourcePath(JspCompilationContext.java:536)
at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:469)
at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1430)
at org.apache.jasper.compiler.Parser.parse(Parser.java:139)
at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:227)
at org.apache.jasper.compiler.ParserController.parse(ParserController.java:100)
at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:199)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:356)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:336)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:323)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:570)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:356)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.wso2.carbon.ui.JspServlet.service(JspServlet.java:155)
at org.wso2.carbon.ui.TilesJspServlet.service(TilesJspServlet.java:80)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.eclipse.equinox.http.helper.ContextPathServletAdaptor.service(ContextPathServletAdaptor.java:37)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:128)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:68)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.wso2.carbon.tomcat.ext.servlet.DelegationServlet.service(DelegationServlet.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
at org.eclipse.equinox.http.servlet.internal.RequestDispatcherAdaptor.forward(RequestDispatcherAdaptor.java:30)
at org.eclipse.equinox.http.helper.ContextPathServletAdaptor$RequestDispatcherAdaptor.forward(ContextPathServletAdaptor.java:362)
at org.apache.tiles.servlet.context.ServletTilesRequestContext.forward(ServletTilesRequestContext.java:198)
at org.apache.tiles.servlet.context.ServletTilesRequestContext.dispatch(ServletTilesRequestContext.java:185)
at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:419)
at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:370)
at org.wso2.carbon.ui.action.ActionHelper.render(ActionHelper.java:52)
at org.wso2.carbon.ui.TilesJspServlet.service(TilesJspServlet.java:101)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.eclipse.equinox.http.helper.ContextPathServletAdaptor.service(ContextPathServletAdaptor.java:37)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:128)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:68)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.wso2.carbon.tomcat.ext.servlet.DelegationServlet.service(DelegationServlet.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.wso2.carbon.tomcat.ext.filter.CharacterSetFilter.doFilter(CharacterSetFilter.java:61)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.continueInvocation(CompositeValve.java:99)
at org.wso2.carbon.tomcat.ext.valves.TomcatValveContainer.invokeValves(TomcatValveContainer.java:49)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.invoke(CompositeValve.java:62)
at org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:159)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.wso2.carbon.tomcat.ext.valves.CarbonContextCreatorValve.invoke(CarbonContextCreatorValve.java:57)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
I debug the tomcat8 source and found that tldCache inside the EmbeddedServletOption is null. This is been set by the onStartup method in the JasperInitializer
What can I do to make sure that it get invoke
or how can I manually invoke org.apache.jasper.servlet.JasperInitializer.onStartup
during web app startup?
I'm embedding tomcat 8 inside the application.
回答1:
The solution to this issue is somewhat hidden and doesn't seem to be documented but it can sometimes be solved with one line of code.
context.addServletContainerInitializer(new JasperInitializer(), null);
I admit the server is slow to start once this is added, but it is now functional.
来源：https://stackoverflow.com/questions/29097407/jasperinitializer-in-tomcat-8-embedded-mode