java - tomcat 8 嵌入式模式下的 JasperInitializer

Question

我正在将嵌入式 tomcat 应用程序从 7.0.59 迁移到 tomcat 8.0.20在我启动嵌入式服务器并尝试访问主页时更新 Tomcat 版本后，我得到了一个 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)

调试tomcat8源码，发现EmbeddedServletOption里面的tldCache为null。这是由 JasperInitializer

中的 onStartup 方法设置的

我该怎么做才能确保它被调用或者我如何手动调用 org.apache.jasper.servlet.JasperInitializer.onStartup在网络应用程序启动期间？

我在应用程序中嵌入了 tomcat 8。

Answer 1

这个问题的解决方案有些隐蔽，似乎没有记录在案，但有时可以用一行代码解决。

context.addServletContainerInitializer(new JasperInitializer(), null);

我承认添加后服务器启动速度很慢，但现在可以正常使用了。