Jasper_filter data_pass field data from main to sub to filter some data

main report:

1 add variable

<variable name="Variable_rule" class="java.lang.String" resetType="None">
    <variableExpression><![CDATA[$F{rule name}]]></variableExpression>
    <initialValueExpression><![CDATA[$F{rule name}]]></initialValueExpression>
</variable>

2 add subreportParameter

<subreport>
    <reportElement x="-20" y="0" width="480" height="100" uuid="65fbc18f-3989-4701-ba4a-da8222d0a54d">
        <property name="com.jaspersoft.studio.unit.x" value="pixel"/>
        <property name="com.jaspersoft.studio.unit.y" value="pixel"/>
    </reportElement>
    <subreportParameter name="P_ruleName">
        <subreportParameterExpression><![CDATA[$V{Variable_rule}]]></subreportParameterExpression>
    </subreportParameter>
    <dataSourceExpression><![CDATA[$P{REPORT_DATA_SOURCE}]]></dataSourceExpression>
    <subreportExpression><![CDATA["src/table/jasper/Blank_A4_1.jasper"]]></subreportExpression>
</subreport>

subreport: 

1 add parameter

<parameter name="P_ruleName" class="java.lang.String"/>

2 filter data

<filterExpression><![CDATA[$V{Variable_rule}.equals($P{P_ruleName})]]></filterExpression>