JBWEB000236：servlet jsp的Servlet.service（）抛出异常：java.lang.NullPointerException：value为null

Question

嗨，我是JBoss的新手，并试图在JBoss EAP 6部署我的网络应用程序。部署成功，在尝试访问应用程序时，我得到以下异常。我正在使用logback和slf4j登录我的应用程序。任何人都可以帮我找到解决方案

12:04:12,846 INFO  [org.jboss.as] (Controller Boot Thread) JBAS015874: JBoss EAP 6.2.0.GA (AS 7.3.0.Final-redhat-14) started in 37270ms - Started 185 of 245 services (59 services are passive or on-demand)
12:19:32,799 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/SynergyClient].[jsp]] (http-/127.0.0.1:9090-1) JBWEB000236: Servlet.service() for servlet jsp threw exception: java.lang.NullPointerException: value is null
    at org.jboss.logmanager.MDC.put(MDC.java:58) [jboss-logmanager-1.5.1.Final-redhat-1.jar:1.5.1.Final-redhat-1]
    at org.slf4j.impl.Slf4jMDCAdapter.put(Slf4jMDCAdapter.java:32)
    at org.slf4j.MDC.put(MDC.java:116) [slf4j-api-1.7.2.redhat-2.jar:1.7.2.redhat-2]
    at ch.qos.logback.classic.helpers.MDCInsertingServletFilter.insertIntoMDC(MDCInsertingServletFilter.java:70) [logback-classic-1.0.13.jar:]
    at ch.qos.logback.classic.helpers.MDCInsertingServletFilter.doFilter(MDCInsertingServletFilter.java:49) [logback-classic-1.0.13.jar:]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:149) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:169) [jboss-as-web-7.3.0.Final-redhat-14.jar:7.3.0.Final-redhat-14]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:145) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:97) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:102) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:336) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:653) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:920) [jbossweb-7.2.2.Final-redhat-1.jar:7.2.2.Final-redhat-1]
    at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_09]

Answer 1

java.lang.NullPointerException：value为null

这是一个非常直接的例外。我的建议是逐个调试传递给JSP的值。

你的变量value被传递为null。检查参数的名称是否匹配，以及正确的参数变量是否存在正确的getter / setter