Error in XSLT: There are several Java methods that match equally

[kkk_f17]

while i'm running the below code, I'm getting : "There are several Java methods that match equally well". Can any one solve this problem. Please i need u r help. Thanks in Advance

My XML:--

<?xml version="1.0" encoding="UTF-8"?>
<article1>
<title>kiran Java May Be a Fad</title>
<author>J. Burke</author>
<startdate>25/12/2009</startdate>
<enddate>30/10/2010</enddate>
</article1>

My XSLT:--

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0" xmlns:java="xalan://java.util.GregorianCalendar"
extension-element-prefixes="java">

<xsl:template match="article1">

<xsl:if test="startdate[.!=''] or enddate[.!='']">

<xsl:variable name="startDateCal" select="java:new(.)"/>

<xsl:variable name="sday" select="substring(startdate,1,2)"/>
<xsl:variable name="smonth" select="substring(startdate,4,2)"/>
<xsl:variable name="syear" select="substring(startdate,7,4)"/>
<xsl:variable name="sSetCalender" select="java:startDateCal.set($syear,$smonth,$sday)"/>
<xsl:variable name="sMilliSeconds" select="java:sSetCalender.getTimeInMillis()"/>
<Days>
<xsl:value-of select="$sday"/>
</Days>
</xsl:if>
</xsl:template>

</xsl:stylesheet>