loading java applet failed

I noted that coldfusion run " MultiBarChart.class" with this cfm file:

<cfquery name="GetData"
datasource=#Cookie.AFMDSN#>
SELECT bl_id, fl_id, ( {fn CONCAT( dv_id, {fn CONCAT('-', dp_id)} )} ) AS bdd, ROUND(SUM(area),0) as area
FROM rm
WHERE bl_id = '#var_rm_bl_id#'
GROUP BY bl_id, fl_id, dv_id, dp_id
ORDER BY bl_id, fl_id DESC, bdd
</cfquery>


<CFIF IsDefined("URL.SuperCat")>
<CFCOOKIE NAME="hotlist_SuperCat" VALUE=#URL.SuperCat# >
</CFIF>
<CFIF IsDefined("URL.Cat")>
<CFCOOKIE NAME="hotlist_Cat" VALUE=#URL.Cat# >
</CFIF>

<p><p>
<!--- Display The Graph --->
<applet codebase="/Classes/CFGraphs/" code="MultiBarChart.class" width=100% height=90%>

<!--- Set the optional display parameters --->
<PARAM NAME="Title" VALUE="Departmental Stack Plan">
<PARAM NAME="TitleFontName" VALUE="Arial">
<PARAM NAME="TitleFontHeight" VALUE="14">
<param name="ShowLegend" value="yes">
<param name="LegendFontName" value="Arial">
<PARAM NAME="LegendFontHeight" VALUE="12">
<PARAM NAME="DrawBorders" VALUE="yes">
<param name="ShowDateTime" value="No">
<PARAM NAME="Orientation" VALUE="horizontal">


<!--- Set required record set parameters --->
<PARAM NAME="ChartData.Rows" VALUE="<cfoutput>#GetData.RecordCount#</cfoutput>">
<PARAM NAME="ChartData.Columns" VALUE="Groups,Items,Values">
<PARAM NAME="ChartData.Groups" VALUE="<CFOUTPUT QUERY="GetData">#bl_id# #fl_id#,</CFOUTPUT>">
<PARAM NAME="ChartData.Items" VALUE="<CFOUTPUT QUERY="GetData">#bdd#,</CFOUTPUT>">
<PARAM NAME="ChartData.Values" VALUE="<CFOUTPUT>#ValueList(GetData.area)#</CFOUTPUT>">

</applet>

Before loading java applet failed I get:
java.lang.nullpointerexception

Have you any idea why I have this error?

Thanks