How to use relative path to reference json schema when exporting to Json? - jasper-reports

Question

I have a report as simple as this:
<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="testJsonExportWithSchema" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="f59243f1-8df7-4c2a-b075-3ca20c4b17f2">
<property name="com.jaspersoft.studio.data.defaultdataadapter" value="One Empty Record"/>
<property name="net.sf.jasperreports.export.json.schema" value="schema.json"/>
<queryString>
<![CDATA[]]>
</queryString>
<detail>
<band height="63" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="555" height="63" uuid="7801126d-70f5-4d0c-9c19-3588dc5fce40">
<property name="net.sf.jasperreports.export.json.path" value="key"/>
</reportElement>
<textFieldExpression><![CDATA["value"]]></textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
And would like to export it to Json using below Json schema:
{
_type: 'object',
key: 'value'
}
Using a relative path to schema (as I do with subreports, images and other resources on the same folder):
<property name="net.sf.jasperreports.export.json.schema" value="schema.json"/>
I get this:
net.sf.jasperreports.engine.JRException: Input stream not found at: schema.json
If I use absolute path it works fine:
<property name="net.sf.jasperreports.export.json.schema" value="c:\users\username\path\to\schema.json"/>
This need for an absolute path is preventing me from using Json schemas in JasperReports Server too.