我正在尝试使用 netbeans 运行 jsf 应用程序，并且在 URLEncode 中出现 NullPointerException 异常。我认为 Servlet 有一些问题，但我不知道如何解决它来源:https://github.com/agoncal/agoncal-application-petstore-ee6
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
java.lang.NullPointerException
at java.net.URLEncoder.encode(URLEncoder.java:204)
at com.sun.faces.context.UrlBuilder.addValuesToParameter(UrlBuilder.java:318)
at com.sun.faces.context.UrlBuilder.addParameters(UrlBuilder.java:127)
at com.sun.faces.context.ExternalContextImpl.encodeBookmarkableURL(ExternalContextImpl.java:1054)
at com.sun.faces.application.view.MultiViewHandler.getBookmarkableURL(MultiViewHandler.java:407)
at javax.faces.application.ViewHandlerWrapper.getBookmarkableURL(ViewHandlerWrapper.java:272)
at org.jboss.weld.jsf.ConversationAwareViewHandler.getBookmarkableURL(ConversationAwareViewHandler.java:132)
at com.sun.faces.renderkit.html_basic.OutcomeTargetRenderer.getEncodedTargetURL(OutcomeTargetRenderer.java:194)
at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.renderAsActive(OutcomeTargetLinkRenderer.java:158)
at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.encodeBegin(OutcomeTargetLinkRenderer.java:96)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Warning: StandardWrapperValve[Faces Servlet]: Servlet.service() for servlet Faces Servlet threw exception
java.lang.NullPointerException
at java.net.URLEncoder.encode(URLEncoder.java:204)
at com.sun.faces.context.UrlBuilder.addValuesToParameter(UrlBuilder.java:318)
at com.sun.faces.context.UrlBuilder.addParameters(UrlBuilder.java:127)
at com.sun.faces.context.ExternalContextImpl.encodeBookmarkableURL(ExternalContextImpl.java:1054)
at com.sun.faces.application.view.MultiViewHandler.getBookmarkableURL(MultiViewHandler.java:407)
at javax.faces.application.ViewHandlerWrapper.getBookmarkableURL(ViewHandlerWrapper.java:272)
at org.jboss.weld.jsf.ConversationAwareViewHandler.getBookmarkableURL(ConversationAwareViewHandler.java:132)
at com.sun.faces.renderkit.html_basic.OutcomeTargetRenderer.getEncodedTargetURL(OutcomeTargetRenderer.java:194)
at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.renderAsActive(OutcomeTargetLinkRenderer.java:158)
at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.encodeBegin(OutcomeTargetLinkRenderer.java:96)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
当我转到index.xhtml时它就会出现
最佳答案
从下到上阅读堆栈跟踪并选择相关行以了解流程。
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
因此，FacesServlet 被调用并为请求提供服务。
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120
因此，执行渲染响应阶段。
<小时/> at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
因此将呈现 Facelets (XHTML) 文件。
<小时/> at com.sun.faces.renderkit.html_basic.OutcomeTargetLinkRenderer.encodeBegin(OutcomeTargetLinkRenderer.java:96)
因此，正在渲染 <h:link>。
at com.sun.faces.renderkit.html_basic.OutcomeTargetRenderer.getEncodedTargetURL(OutcomeTargetRenderer.java:194)
因此，它需要渲染目标 URL。
<小时/> at com.sun.faces.context.UrlBuilder.addParameters(UrlBuilder.java:127)
因此，该链接具有需要添加到目标 URL 的 <f:param> 值。
at java.net.URLEncoder.encode(URLEncoder.java:204)
并且它们需要进行 URL 编码。
<小时/>java.lang.NullPointerException
但是，value 的 <f:param> 的 <h:link> 似乎是 null 。
我想你现在明白了吗？
关于jsf - java.lang.NullPointerException 在 java.net.URLEncoder.encode 在 com.sun.faces.context.UrlBuilder.addValuesToParameter，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30558660/