Why do I get a Java Exception when I use 'doc' command (2018b)

Question

Richard Stephens 2018-10-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/423212-why-do-i-get-a-java-exception-when-i-use-doc-command-2018b

回答： Richard Stephens 2018-11-13

采纳的回答： Richard Stephens

在 MATLAB Online 中打开

When using the 'doc' command with a string that is not a command, e.g.:

doc classes

I get a Java Exception event:

Exception in thread "AWT-EventQueue-0": java.lang.NullPointerException
  at com.mathworks.help.helpui.DocRoot.buildDocPageUrl(DocRoot.java:44)
  at com.mathworks.help.helpui.DocPageUrlBuilder.buildDocPageUrl(DocPageUrlBuilder.java:25)
  at com.mathworks.help.helpui.DocPageUrlBuilder.buildFileUrl(DocPageUrlBuilder.java:21)
  at com.mathworks.mlwidgets.help.LightweightHelpPanel$JsHelpPanelClientRunnable.getUrlToLoad(LightweightHelpPanel.java:224)
  at com.mathworks.mlwidgets.help.LightweightHelpPanel$JsHelpPanelClientRunnable.run(LightweightHelpPanel.java:208)
  at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
  at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
  at java.awt.EventQueue.access$500(EventQueue.java:97)
  at java.awt.EventQueue$3.run(EventQueue.java:709)
  at java.awt.EventQueue$3.run(EventQueue.java:703)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
  at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
  at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
  at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)