XSLT extention problem

hi there,

I am writing an Java extention for my XSLT.

There are two static method in the java code, there are:

int getHeight(String path);
int getWidth(String path);


package com.atomsoft.app.graphictools;

import java.io.File;

import javax.swing.ImageIcon;

public class GraphicInfo
{
public static int getWidth(String path)
{
int width = 0;

String temp_path = path.replace("/", File.separator);
temp_path = temp_path.substring(6);

ImageIcon icon = new ImageIcon(temp_path);
width = icon.getIconWidth();

return width;
}

public static int getHeight(String path)
{
int height = 0;

String temp_path = path.replace("/", File.separator);
temp_path = temp_path.substring(6);

ImageIcon icon = new ImageIcon(temp_path);
height = icon.getIconHeight();

return height;
}
}


The following is my XSLT:

<?xml version="1.0" encoding="utf-8"?>

<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:atomExt="com.atomsoft.app.graphictools.GraphicInfo"
version="2.0">

<xsl:param name="max_width" select="500"/>

<xsl:output method="xml" encoding="UTF-8" indent="yes"/>

<xsl:template match="SHEET">
<xsl:element name="{name()}">
<xsl:variable name="v_filepath" select="unparsed-entity-uri(@GNBR)"/>
<xsl:variable name="v_org_width" select="atomExt:getWidth($v_filepath)"/>
<xsl:variable name="v_org_height" select="atomExt:getHeight($v_filepath)"/>


<xsl:variable name="v_new_width">
<xsl:choose>
<xsl:when test="$v_org_width &gt; $max_width"><xsl:value-of
select="$max_width"/></xsl:when>
<xsl:otherwise><xsl:value-of select="$v_org_width"/></xsl:otherwise>
</xsl:choose>
</xsl:variable>

<xsl:variable name="v_new_height" select="round($v_org_height *
$v_new_width div $v_org_width)"/>

<xsl:attribute name="WIDTH" select="$v_new_width"/>
<xsl:attribute name="HEIGHT" select="$v_new_height"/>

<xsl:for-each select="@*">
<xsl:if test="not(name(.)='WIDTH' or name(.)='HEIGHT')">
<xsl:apply-templates select="."/>
</xsl:if>
</xsl:for-each>

<xsl:apply-templates select="*"/>


</xsl:element>


</xsl:template>

<xsl:template match="*">
<xsl:element name="{name()}">
<xsl:apply-templates select="@*|node()"/>
</xsl:element>
</xsl:template>

<xsl:template match="@*">
<xsl:attribute name="{name()}">
<xsl:value-of select="."/>
</xsl:attribute>
</xsl:template>

</xsl:transform>



The xslt works. My problem is:
I tested the java code stand alone. It works fine. But when I call the
java method in my XSLT, The result file is generated but the xslt
command line is hanged.

It seems this problem have something to do the following java code:

ImageIcon icon = new ImageIcon(temp_path);
height = icon.getIconHeight();

If I do not use this class (ImageIcon), it works fine in XSLT. Is there
some special thing in this class?

I am using Saxon 8.9 as my XSLT engine.

Thanks

Jingjun