5 Replies Latest reply on Jul 13, 2010 5:52 AM by hoang_to

Portlet Edit mode throws NullPointer (GateIn 3.1)

g.nuijen Jun 25, 2010 9:14 AM

Hello,

I am trying to create a portlet with an edit mode, but I am running into some troubles. It is based on PortletBridge 2.0.0.FINAL + seam and facelets.

portlet.xml:

<portlet>
<portlet-name>chartPortlet</portlet-name>
<portlet-class>javax.portlet.faces.GenericFacesPortlet</portlet-class>
 
<init-param>
<name>javax.portlet.faces.defaultViewId.view</name>
<value>/chart.xhtml</value>
</init-param>
<init-param>
<name>javax.portlet.faces.defaultViewId.edit</name>
<value>/chart_config.xhtml</value>
</init-param>
<init-param>
<name>javax.portlet.faces.preserveActionParams</name>
<value>true</value>
</init-param>
<init-param>
<name>javax.portlet.faces.autoDispatchEvents</name>
<value>true</value>
</init-param>
<expiration-cache>-0</expiration-cache>
<supports>
<mime-type>text/html</mime-type>
<portlet-mode>VIEW</portlet-mode>
<portlet-mode>EDIT</portlet-mode>
</supports>
<portlet-info>
<title>Chart portlet</title>
</portlet-info>
<portlet-preferences>
<preference>
<name>chartXml</name>
<value>/charts/chart1.xml</value>
</preference>
</portlet-preferences>
</portlet>

/chart_config.xhtml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<f:view xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">

<p>Simple message</p>

</f:view>

As you can see, there is nothing special in the page. It should just display a simple message.

Exception:

java.lang.NullPointerException
     at java.lang.String.<init>(String.java:515)
     at org.exoplatform.portal.webui.application.UIPortletForm.getEditModeContent(UIPortletForm.java:221)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:597)
     at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:229)

I traced it in the sourcecode to:

         String content;
         if (portletResponse instanceof FragmentResponse)
         {
            FragmentResponse fragmentResponse = (FragmentResponse)portletResponse;
            content = new String(fragmentResponse.getBytes(), "UTF-8");
         }

The result of getBytes() seems to be null.

What am I doing wrong?

1. Re: Portlet Edit mode throws NullPointer (GateIn 3.1)

g.nuijen Jun 29, 2010 5:52 AM (in response to g.nuijen)

I have just tested with the jsfhouser gatein example and it gives the exact same error + stacktrace.

So I think I am not doing anything wrong. I will retest with gatein 3.0 FINAL, maybe it is a problem with 3.1.

update:
It works in 3.0, but not in 3.1.

Ok, I figured it out. The problem was introduced with the bug fix of https://jira.jboss.org/browse/GTNPORTAL-1228.

The root cause was the lack of Charset while processing FragmentResponse in getEditModeContent method ( in UIPortletForm class)


        String content;
         if (portletResponse instanceof FragmentResponse)
         {
            FragmentResponse fragmentResponse = (FragmentResponse)portletResponse;
            content = fragmentResponse.getContent();
         }

A slight change was enough to fix the display error

         String content;
         if (portletResponse instanceof FragmentResponse)
         {
            FragmentResponse fragmentResponse = (FragmentResponse)portletResponse;
            content = new String(fragmentResponse.getBytes(), Charset.forName("UTF-8"));
         }

The problem is that FragmentResponse has either chars or bytes:

   public int getType()
   {
      if (bytes == null)
      {
         if (chars == null)
         {
            return TYPE_EMPTY;
         }
         else
         {
            return TYPE_CHARS;
         }
      }
      else
      {
         return TYPE_BYTES;
      }
   }

   /**
    * Return the content as a string.
    *
    * @return the content
    */
   public String getContent()
   {
      switch (getType())
      {
         case TYPE_CHARS:
            return getChars();
         case TYPE_BYTES:
            return new String(bytes);
         case TYPE_EMPTY:
            return "";
         default:
            throw new AssertionError();
      }
   }

Update:

I created a patch and that works. I will try to submit a patch.

            FragmentResponse fragmentResponse = (FragmentResponse)portletResponse;
            if (fragmentResponse.getType() == FragmentResponse.TYPE_BYTES) {
                 content = new String(fragmentResponse.getBytes(), "UTF-8");
            } else {
                content = fragmentResponse.getContent();
            }
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2. Re: Portlet Edit mode throws NullPointer (GateIn 3.1)

g.nuijen Jun 29, 2010 5:53 AM (in response to g.nuijen)

Was a bug in 3.1.
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3. Re: Portlet Edit mode throws NullPointer (GateIn 3.1)

trong.tran Jun 29, 2010 6:23 AM (in response to g.nuijen)

Yes, this is definitely a bug in 3.1

Thanks for your perfect investigation and the patch, Gerbert
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4. Re: Portlet Edit mode throws NullPointer (GateIn 3.1)

hoang_to Jul 13, 2010 3:41 AM (in response to trong.tran)

It is a bug introduced by my fix for GTNPORTAL-1288. Thanks for the patch, it seems to be the proper fix
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5. Re: Portlet Edit mode throws NullPointer (GateIn 3.1)

hoang_to Jul 13, 2010 5:52 AM (in response to hoang_to)

The types of FragmentResponse returned on invoking a portlet depends on what portlet developer does to generate response: Writes characters to PortletResponse.getWriter() , writes bytes to PortletResponse.getPortletOutputStream() or do nothing.
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