为什么只显示我的第一个子报表？
Why does only my first subreport display?
我正在尝试在一个 Jasper Report 中显示多个表格，并且为此功能使用了子报表。但我坚持显示几个子报告。实际上，只显示其中一个（第一个）。
这是我的主要report.jrxml:
<?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="multitable" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="1c6dc1c9-67af-43d5-bf1e-9243557c8048">
<property name="net.sf.jasperreports.json.source" value="C:/jdd/projects/StackTrace/jasper/multitable.json"/>
<parameter name="SUBREPORT_DIR" class="java.lang.String" isForPrompting="false">
<defaultValueExpression><![CDATA["reports/hardware/"]]></defaultValueExpression></parameter>
<parameter name="title" class="java.lang.String"/>
<parameter name="period" class="java.lang.String"/>
<parameter name="DS1" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
<parameter name="DS2" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
<queryString language="json">
<![CDATA[]]>
</queryString>
<detail>
<band height="120" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="50" uuid="91249d6e-57f7-4b6d-8d2a-05059efa2a47"/>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font size="16"/>
</textElement>
<textFieldExpression><![CDATA[$P{title}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="652" y="0" width="100" height="50" uuid="67e1ca07-588a-4b2b-ae93-ecbdb544b01b"/>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font size="16"/>
</textElement>
<textFieldExpression><![CDATA[$P{period}]]></textFieldExpression>
</textField>
<subreport>
<reportElement x="0" y="50" width="555" height="20" uuid="48a7bbe4-b8ce-4a0d-a6e1-6ddd288e5602"/>
<dataSourceExpression><![CDATA[$P{DS1}]]></dataSourceExpression>
<subreportExpression><![CDATA[$P{SUBREPORT_DIR} + "printersSubreport.jasper"]]></subreportExpression>
</subreport>
</band>
</detail>
<summary>
<band height="305" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="50" uuid="91249d6e-57f7-4b6d-8d2a-05059efa2a47"/>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font size="16"/>
</textElement>
<textFieldExpression><![CDATA[$P{title}]]></textFieldExpression>
</textField>
<subreport>
<reportElement x="0" y="50" width="555" height="32" uuid="780a1f25-065e-494a-ba1d-86a33b464343"/>
<dataSourceExpression><![CDATA[$P{DS2}]]></dataSourceExpression>
<subreportExpression><![CDATA[$P{SUBREPORT_DIR} + "subjectSubreport.jasper"]]></subreportExpression>
</subreport>
</band>
</summary>
</jasperReport>
这里是 subjectSubreport.jrxml:
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.9.0.final using JasperReports Library version 6.9.0-cb8f9004be492ccc537180b49c026951f4220bf3 -->
<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="multitable_summary" pageWidth="555" pageHeight="802" columnWidth="555" leftMargin="0" rightMargin="0" topMargin="0" bottomMargin="0" uuid="2a869c20-1e7d-4baa-92d7-c8d555f1f344">
<queryString language="json">
<![CDATA[]]>
</queryString>
<field name="subject" class="java.lang.String"/>
<field name="zipCode" class="java.lang.Integer"/>
<background>
<band splitType="Stretch"/>
</background>
<title>
<band height="23">
<staticText>
<reportElement x="0" y="0" width="100" height="20" uuid="a9730039-8418-4e58-a2eb-0babe8d2a380"/>
<text><![CDATA[Subject]]></text>
</staticText>
</band>
</title>
<columnHeader>
<band height="20">
<staticText>
<reportElement mode="Opaque" x="0" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="a49b18ef-63c3-42bb-ae81-8d7d72ac9086"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<text><![CDATA[Subject]]></text>
</staticText>
<staticText>
<reportElement mode="Opaque" x="100" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="c1c70fed-d887-429f-a3b0-ed645517e41f"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<text><![CDATA[ZipCode]]></text>
</staticText>
</band>
</columnHeader>
<detail>
<band height="20" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="20" uuid="401436b3-d9a1-40bd-8a1d-dfa3f162f842"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{subject}]]></textFieldExpression>
</textField>
<textField pattern="###0">
<reportElement x="100" y="0" width="100" height="20" uuid="4447d3b0-6d3e-4795-8b5f-6a09d620448b"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{zipCode}]]></textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
这里是 printersSubreport.jrxml：
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.9.0.final using JasperReports Library version 6.9.0-cb8f9004be492ccc537180b49c026951f4220bf3 -->
<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="multitable_subreport" pageWidth="555" pageHeight="802" whenNoDataType="AllSectionsNoDetail" columnWidth="555" leftMargin="0" rightMargin="0" topMargin="0" bottomMargin="0" uuid="5f89d251-66b1-4658-9af5-c057de138fb6">
<field name="statusDesc" class="java.lang.String"/>
<field name="lastUpdateTime" class="java.lang.Integer"/>
<field name="criticalCount" class="java.lang.String"/>
<columnHeader>
<band height="20" splitType="Stretch">
<staticText>
<reportElement mode="Opaque" x="0" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="bbb8857c-471c-4aca-a8fc-336d2748d7b9"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<text><![CDATA[Description]]></text>
</staticText>
<staticText>
<reportElement mode="Opaque" x="100" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="3fde89c9-d9a3-4972-8e3b-b2e619a51601"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<text><![CDATA[UpdateTime]]></text>
</staticText>
<staticText>
<reportElement mode="Opaque" x="200" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="e82ece60-c92e-4d0b-8881-29d7d0d78e81"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<text><![CDATA[Count]]></text>
</staticText>
</band>
</columnHeader>
<detail>
<band height="20" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="20" uuid="cdec861a-8b3b-413f-8b99-74d0e18ee19d"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{statusDesc}]]></textFieldExpression>
</textField>
<textField pattern="###0.##">
<reportElement x="100" y="0" width="100" height="20" uuid="9dfb9f78-74e5-4562-84fd-ebb87c3203ce"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{lastUpdateTime}]]></textFieldExpression>
</textField>
<textField pattern="¤ #,##0.00">
<reportElement x="200" y="0" width="100" height="20" uuid="923ff62d-ea1f-410e-94d3-fa7c574c001b"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{criticalCount}]]></textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
当我切换子报告时，第一个正确显示，另一个消失。在 JasperSoft Studio 中一切正常，当我将它们导出到 pdf/xls 时问题就开始了。
Actually, only one of them (the first) is displayed.. When I switch sub reports the first of them displays correctly, and the other one disappears
您声明：
<parameter name="DS1" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
<parameter name="DS2" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
JRDatasource 是可消耗的，这意味着如果您使用它来填充一个报告，它将被消耗，因此下一个报告在同一数据源上调用 next() 将 return 为假。
如果您为 DS1 和 DS2 传递 same（相同的对象）数据源，您遇到的情况是，DS1 将用于填充第一个子报表，然后由于 DS1 == DS2 DS2 在填充第二个子报表时已经被消耗，第二个报表将没有记录（空）。
解决方案
您需要制作一个克隆 DS1，创建一个新对象并将其作为 DS2 传递。 JsonDataSource 理论上也是一个 JRRewindableDataSource，因此您可以在填充第二个子报表之前调用 moveFirst()，但这在 jrxml 文件中不是很容易，所以我不建议尝试使用它方法。
我正在尝试在一个 Jasper Report 中显示多个表格，并且为此功能使用了子报表。但我坚持显示几个子报告。实际上，只显示其中一个（第一个）。
这是我的主要report.jrxml:
<?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="multitable" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="1c6dc1c9-67af-43d5-bf1e-9243557c8048">
<property name="net.sf.jasperreports.json.source" value="C:/jdd/projects/StackTrace/jasper/multitable.json"/>
<parameter name="SUBREPORT_DIR" class="java.lang.String" isForPrompting="false">
<defaultValueExpression><![CDATA["reports/hardware/"]]></defaultValueExpression></parameter>
<parameter name="title" class="java.lang.String"/>
<parameter name="period" class="java.lang.String"/>
<parameter name="DS1" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
<parameter name="DS2" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
<queryString language="json">
<![CDATA[]]>
</queryString>
<detail>
<band height="120" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="50" uuid="91249d6e-57f7-4b6d-8d2a-05059efa2a47"/>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font size="16"/>
</textElement>
<textFieldExpression><![CDATA[$P{title}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="652" y="0" width="100" height="50" uuid="67e1ca07-588a-4b2b-ae93-ecbdb544b01b"/>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font size="16"/>
</textElement>
<textFieldExpression><![CDATA[$P{period}]]></textFieldExpression>
</textField>
<subreport>
<reportElement x="0" y="50" width="555" height="20" uuid="48a7bbe4-b8ce-4a0d-a6e1-6ddd288e5602"/>
<dataSourceExpression><![CDATA[$P{DS1}]]></dataSourceExpression>
<subreportExpression><![CDATA[$P{SUBREPORT_DIR} + "printersSubreport.jasper"]]></subreportExpression>
</subreport>
</band>
</detail>
<summary>
<band height="305" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="50" uuid="91249d6e-57f7-4b6d-8d2a-05059efa2a47"/>
<textElement textAlignment="Center" verticalAlignment="Middle">
<font size="16"/>
</textElement>
<textFieldExpression><![CDATA[$P{title}]]></textFieldExpression>
</textField>
<subreport>
<reportElement x="0" y="50" width="555" height="32" uuid="780a1f25-065e-494a-ba1d-86a33b464343"/>
<dataSourceExpression><![CDATA[$P{DS2}]]></dataSourceExpression>
<subreportExpression><![CDATA[$P{SUBREPORT_DIR} + "subjectSubreport.jasper"]]></subreportExpression>
</subreport>
</band>
</summary>
</jasperReport>
这里是 subjectSubreport.jrxml:
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.9.0.final using JasperReports Library version 6.9.0-cb8f9004be492ccc537180b49c026951f4220bf3 -->
<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="multitable_summary" pageWidth="555" pageHeight="802" columnWidth="555" leftMargin="0" rightMargin="0" topMargin="0" bottomMargin="0" uuid="2a869c20-1e7d-4baa-92d7-c8d555f1f344">
<queryString language="json">
<![CDATA[]]>
</queryString>
<field name="subject" class="java.lang.String"/>
<field name="zipCode" class="java.lang.Integer"/>
<background>
<band splitType="Stretch"/>
</background>
<title>
<band height="23">
<staticText>
<reportElement x="0" y="0" width="100" height="20" uuid="a9730039-8418-4e58-a2eb-0babe8d2a380"/>
<text><![CDATA[Subject]]></text>
</staticText>
</band>
</title>
<columnHeader>
<band height="20">
<staticText>
<reportElement mode="Opaque" x="0" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="a49b18ef-63c3-42bb-ae81-8d7d72ac9086"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<text><![CDATA[Subject]]></text>
</staticText>
<staticText>
<reportElement mode="Opaque" x="100" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="c1c70fed-d887-429f-a3b0-ed645517e41f"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<text><![CDATA[ZipCode]]></text>
</staticText>
</band>
</columnHeader>
<detail>
<band height="20" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="20" uuid="401436b3-d9a1-40bd-8a1d-dfa3f162f842"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{subject}]]></textFieldExpression>
</textField>
<textField pattern="###0">
<reportElement x="100" y="0" width="100" height="20" uuid="4447d3b0-6d3e-4795-8b5f-6a09d620448b"/>
<box leftPadding="0">
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{zipCode}]]></textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
这里是 printersSubreport.jrxml：
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.9.0.final using JasperReports Library version 6.9.0-cb8f9004be492ccc537180b49c026951f4220bf3 -->
<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="multitable_subreport" pageWidth="555" pageHeight="802" whenNoDataType="AllSectionsNoDetail" columnWidth="555" leftMargin="0" rightMargin="0" topMargin="0" bottomMargin="0" uuid="5f89d251-66b1-4658-9af5-c057de138fb6">
<field name="statusDesc" class="java.lang.String"/>
<field name="lastUpdateTime" class="java.lang.Integer"/>
<field name="criticalCount" class="java.lang.String"/>
<columnHeader>
<band height="20" splitType="Stretch">
<staticText>
<reportElement mode="Opaque" x="0" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="bbb8857c-471c-4aca-a8fc-336d2748d7b9"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<text><![CDATA[Description]]></text>
</staticText>
<staticText>
<reportElement mode="Opaque" x="100" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="3fde89c9-d9a3-4972-8e3b-b2e619a51601"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<text><![CDATA[UpdateTime]]></text>
</staticText>
<staticText>
<reportElement mode="Opaque" x="200" y="0" width="100" height="20" backcolor="#CCCCCC" uuid="e82ece60-c92e-4d0b-8881-29d7d0d78e81"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<text><![CDATA[Count]]></text>
</staticText>
</band>
</columnHeader>
<detail>
<band height="20" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="20" uuid="cdec861a-8b3b-413f-8b99-74d0e18ee19d"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{statusDesc}]]></textFieldExpression>
</textField>
<textField pattern="###0.##">
<reportElement x="100" y="0" width="100" height="20" uuid="9dfb9f78-74e5-4562-84fd-ebb87c3203ce"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{lastUpdateTime}]]></textFieldExpression>
</textField>
<textField pattern="¤ #,##0.00">
<reportElement x="200" y="0" width="100" height="20" uuid="923ff62d-ea1f-410e-94d3-fa7c574c001b"/>
<box>
<pen lineWidth="0.25"/>
<topPen lineWidth="0.25"/>
<leftPen lineWidth="0.25"/>
<bottomPen lineWidth="0.25"/>
<rightPen lineWidth="0.25"/>
</box>
<textElement textAlignment="Center" verticalAlignment="Middle"/>
<textFieldExpression><![CDATA[$F{criticalCount}]]></textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
当我切换子报告时，第一个正确显示，另一个消失。在 JasperSoft Studio 中一切正常，当我将它们导出到 pdf/xls 时问题就开始了。
Actually, only one of them (the first) is displayed.. When I switch sub reports the first of them displays correctly, and the other one disappears
您声明：
<parameter name="DS1" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
<parameter name="DS2" class="net.sf.jasperreports.engine.data.JsonDataSource"/>
JRDatasource 是可消耗的，这意味着如果您使用它来填充一个报告，它将被消耗，因此下一个报告在同一数据源上调用 next() 将 return 为假。
如果您为 DS1 和 DS2 传递 same（相同的对象）数据源，您遇到的情况是，DS1 将用于填充第一个子报表，然后由于 DS1 == DS2 DS2 在填充第二个子报表时已经被消耗，第二个报表将没有记录（空）。
解决方案
您需要制作一个克隆 DS1，创建一个新对象并将其作为 DS2 传递。 JsonDataSource 理论上也是一个 JRRewindableDataSource，因此您可以在填充第二个子报表之前调用 moveFirst()，但这在 jrxml 文件中不是很容易，所以我不建议尝试使用它方法。