奇怪的“字符串索引超出范围：0”错误 [英] strange "String index out of range: 0" error

问题描述

我有一个庞大的应用程序，在某些时候，当涉及重定向时，我收到了这个奇怪的错误：

I have a huge application and at some point, when a redirect is involved i received this strange error:

Caused by java.lang.StringIndexOutOfBoundsException with message: "String index out of range: 0"    
java.lang.String.charAt(String.java:687)
com.sun.faces.application.ViewHandlerImpl.getActionURL(ViewHandlerImpl.java:652)
org.jboss.seam.jsf.SeamViewHandler.getActionURL(SeamViewHandler.java:74)
com.sun.facelets.FaceletViewHandler.getActionURL(FaceletViewHandler.java:803)
org.ajax4jsf.application.ViewHandlerWrapper.getActionURL(ViewHandlerWrapper.java:86)
org.jboss.seam.ui.util.ViewUrlBuilder.<init>(ViewUrlBuilder.java:25)
org.jboss.seam.ui.component.UISeamCommandBase.getUrl(UISeamCommandBase.java:48)
org.jboss.seam.ui.renderkit.LinkRendererBase.doEncodeBegin(LinkRendererBase.java:26)
org.jboss.seam.ui.util.cdk.RendererBase.encodeBegin(RendererBase.java:79)
javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:813)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:934)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:942)
javax.faces.component.UIComponent.encodeAll(UIComponent.java:942)
com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:100)
org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:176)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:109)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:266)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
org.jboss.seam.web.RewriteFilter.doFilter(RewriteFilter.java:63)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:73)
org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53)
org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
java.lang.Thread.run(Thread.java:619)

我花了两个小时调试等等，但没有找到任何线索...
这只是奇怪，因为错误日志没有说明清楚......（哪个字符串，属性涉及等）。

I've spent two hours debugging and so on, but did not find any clue... It's just weird because the error log does not tell something clear...(which string, which property is involved etc).

有没有人可以从堆栈跟踪中猜出更多内容？

Does anyone can guess something more from the stacktrace?

谢谢。

推荐答案

让我们检查 ViewHandlerImpl＃getActionURL（）是什么（ Mojarra只是开源）。这是Mojarra 2.0.2中方法的摘要/剥离摘录：

Let's check what ViewHandlerImpl#getActionURL() does (Mojarra is just open source). Here's is a summarized/stripped extract of the method as it is in Mojarra 2.0.2:

public String getActionURL(FacesContext context, String viewId) {
    if (context == null) throw new NullPointerException();
    if (viewId == null) throw new NullPointerException();
    if (viewId.charAt(0) != '/') throw new IllegalArgumentException();
    // ...

换句话说，传入的 viewId 是一个空字符串而不是 null 或 / 或正常路径。 Mojarra viewhandler根本没想到它，因此这个运行时异常。它可以是Mojarra的视图处理程序中的一个错误，它应该处理空字符串，但它也可能是Ajax4jsf，Facelets或Seam的视图处理程序中的一个错误，它应该永远不会通过一个空字符串。它也可能是您自己的代码中的一个错误，您实际上将空字符串作为视图ID传递。

In other words, the passed-in viewId is an empty string instead of null or / or the normal path. The Mojarra viewhandler didn't expect it at all, hence this runtime exception. It can be a bug in the view handler of Mojarra that it should handle empty strings as well, but it can also be a bug in the view handler of either Ajax4jsf, Facelets or Seam that it should never pass an empty string through up. It can also be a bug in your own code that you're actually passing an empty string as view ID.

如果问题不是'在您的代码中，然后我将开始升级可升级的内容以查看它是否可以解决问题。也许它之前已经被报告为一个bug并在新版本中得到修复。如果这没有帮助，我会检查类路径中是否存在可能相互冲突的不同版本的重复JAR文件。

If the problem isn't in your code, then I would start with upgrading what can be upgraded to see if it resolves the problem. Maybe it was already reported before as a bug and fixed in a newer release. If that doesn't help, I would check the classpath for duplicate JAR files of different versions which might have collided with each other.

这篇关于奇怪的“字符串索引超出范围：0”错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！