java - 通过Java插入的jasper子报表为空

Question

当通过 java 插入子报告时，我在显示子报告时遇到问题。我的目标是动态插入它们，所以我不知道事先会使用哪些子报表。母版页正确显示，而子报表为空白。
似乎我缺少与子报表的连接。也许有人能看出问题出在哪里？很抱歉没有提供最小的工作示例。
这是我设置参数并返回JasperPrint对象的方法:

private JasperPrint createReport(String masterReportFile, String subReportFile, JasperReportFileType fileType, String reportName) throws Exception {
    JRBeanCollectionDataSource ticketsJRBean = new JRBeanCollectionDataSource(workStatList
            .stream()
            .map(this::generateNewJasperReportTicketObject)
            .collect(Collectors.toList()));
    ExternalContext context = FacesContext.getCurrentInstance().getExternalContext();
    InputStream reportTemplate = new FileInputStream(context.getRealPath("") + JasperReportConstants.TemplateLocation.TEMPLATES_DEFAULT.getFullLocation(masterReportFile));
    Map<TemplateLocation, JasperReport> subreportMap = provideRequiredReportsMap(subReportFile, context);
    JasperReport jasperMasterReport = new JasperMasterReport(Optional.of(reportTemplate), reportName, subreportMap).createAndGetJasperReport();
    Map<String, Object> paramsMaster = new HashMap<>();
    setupMasterReportParameters(paramsMaster, fileType);
    Map<String, Object> paramsSub = new HashMap<>();
    paramsMaster.put(JasperTicketReport.PARAM_TICKET_SUBREPORT, subreportList.get(TemplateLocation.TICKETS));
    paramsMaster.put(JasperTicketReport.PARAM_TICKET_DATASOURCE, ticketsJRBean);
    paramsMaster.put(JasperTicketReport.PARAM_HEADER_ID, "HEADER");
    return JasperFillManager.fillReport(jasperMasterReport, paramsMaster);
}

这是类方法，用于创建子报告的链接:

@Override
public JasperReport createAndGetJasperReport() throws Exception {
    try {
        initializeReport();
        subReportMap.forEach((key, value) -> insertSubReport(key, value));
        return JasperCompileManager.compileReport(jasperDesign);
    } catch (JRException ex) {
        LOGGER.log(Level.ERROR, ex.getMessage());
        throw new Exception(ex.getMessage());
    }
}
private void insertSubReport(TemplateLocation templateLocation, JasperReport report) {
    try {
        JRDesignBand subreportBand = new JRDesignBand();
        subreportBand.setHeight(50);
        JRDesignSubreport subreport = new JRDesignSubreport(jasperDesign);
        subreport.setX(0);
        subreport.setY(0);
        subreport.setHeight(20);
        subreport.setWidth(355);
        JRDesignExpression expression = new JRDesignExpression();
        JRDesignSubreportParameter jrDesignSubreportParameterDataSource = new JRDesignSubreportParameter();
        JRDesignSubreportParameter jrDesignSubreportParameterHeaderId = new JRDesignSubreportParameter();
        if (TemplateLocation.TICKETS.equals(templateLocation)) {
            defineParameter(JRBeanCollectionDataSource.class, JasperTicketReport.PARAM_TICKET_DATASOURCE);
            defineParameter(JasperReport.class, JasperTicketReport.PARAM_TICKET_SUBREPORT);
            defineParameter(String.class, JasperTicketReport.PARAM_HEADER_ID);
            expression.setText("$P{" + JasperTicketReport.PARAM_TICKET_SUBREPORT + "}");
            subreport.setExpression(expression);
            expression = new JRDesignExpression();
            expression.setText("$P{" + JasperTicketReport.PARAM_HEADER_ID + "}");
            jrDesignSubreportParameterHeaderId.setExpression(expression);
            jrDesignSubreportParameterHeaderId.setName("ticketHeader");
            subreport.addParameter(jrDesignSubreportParameterHeaderId);
            expression = new JRDesignExpression();
            expression.setText("$P{" + JasperTicketReport.PARAM_TICKET_DATASOURCE + "}");
            jrDesignSubreportParameterDataSource.setExpression(expression);
            jrDesignSubreportParameterDataSource.setName("ticketDataSource");
            subreport.addParameter(jrDesignSubreportParameterDataSource);
        }
        subreportBand.addElement(subreport);
        ((JRDesignSection) jasperDesign.getDetailSection()).addBand(subreportBand);
    } catch (JRException ex) {
        LOGGER.log(Level.ERROR, ex.getMessage());
    }
}

这是我的主 jrxml 文件:

    <?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.11.0.final using JasperReports Library version 6.11.0-0c4056ccaa4d25a5a8c45672d2f764ea3498bebb  -->
<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="Process_A4_Landscape" pageWidth="842" pageHeight="595" orientation="Landscape" columnWidth="802" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="43b18c10-7dae-49ef-ae13-0a6e88c9a593">
    <parameter name="title" class="java.lang.String"/>
    <parameter name="logoBinary" class="java.io.ByteArrayInputStream"/>
    <parameter name="filter" class="java.lang.String"/>
    <parameter name="disp" class="java.lang.String"/>
    <field name="id" class="java.lang.Integer"/>
    <field name="Title" class="java.lang.String">
        <fieldDescription><![CDATA[$P{title}]]></fieldDescription>
    </field>
    <background>
        <band splitType="Stretch"/>
    </background>
    <title>
        <band height="60" splitType="Stretch">
            <image>
                <reportElement x="0" y="0" width="77" height="60" uuid="651ccc4b-e999-40fe-bcbf-1f25bcfc98af"/>
                <imageExpression><![CDATA[$P{logoBinary}]]></imageExpression>
            </image>
            <textField>
                <reportElement x="251" y="0" width="300" height="60" uuid="20b118bd-4ca6-4b6a-993d-19f038c89768">
                    <property name="com.jaspersoft.studio.unit.width" value="px"/>
                </reportElement>
                <textElement textAlignment="Center">
                    <font size="18"/>
                </textElement>
                <textFieldExpression><![CDATA[$P{title}]]></textFieldExpression>
            </textField>
        </band>
    </title>
    <pageHeader>
        <band height="77" splitType="Stretch">
            <textField>
                <reportElement x="53" y="23" width="500" height="30" uuid="ece41608-e59d-4b05-b736-d4c84c420074">
                    <property name="com.jaspersoft.studio.unit.x" value="px"/>
                    <property name="com.jaspersoft.studio.unit.width" value="px"/>
                </reportElement>
                <textElement>
                    <font size="8"/>
                </textElement>
                <textFieldExpression><![CDATA[$P{filter}]]></textFieldExpression>
            </textField>
            <staticText>
                <reportElement x="0" y="23" width="50" height="30" uuid="89f432c5-6e8e-4e56-9317-9131d59e4e31">
                    <property name="com.jaspersoft.studio.unit.x" value="px"/>
                    <property name="com.jaspersoft.studio.unit.width" value="px"/>
                </reportElement>
                <textElement>
                    <font size="8" isBold="true"/>
                </textElement>
                <text><![CDATA[FILTER]]></text>
            </staticText>
        </band>
    </pageHeader>
    <columnHeader>
        <band height="50"/>
    </columnHeader>
    <detail>
        <band height="280" splitType="Stretch"/>
    </detail>
    <pageFooter>
        <band height="69" splitType="Stretch">
            <textField pattern="dd/MM/yyyy HH:mm">
                <reportElement x="50" y="23" width="100" height="30" uuid="6924da96-3fd4-455a-8361-bca736aad641"/>
                <textFieldExpression><![CDATA[new java.util.Date()]]></textFieldExpression>
            </textField>
            <textField>
                <reportElement x="351" y="19" width="100" height="30" uuid="2143305d-6a29-4bc0-a689-1f359db58d49"/>
                <textFieldExpression><![CDATA[$V{PAGE_NUMBER}]]></textFieldExpression>
            </textField>
        </band>
    </pageFooter>
    <summary>
        <band height="46" splitType="Stretch"/>
    </summary>
</jasperReport>

这是我的子报告:

 <?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.11.0.final using JasperReports Library version 6.11.0-0c4056ccaa4d25a5a8c45672d2f764ea3498bebb  -->
<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="Process_A4_Landscape" pageWidth="842" pageHeight="595" orientation="Landscape" columnWidth="802" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="43b18c10-7dae-49ef-ae13-0a6e88c9a593">
    <style name="Table_TH" mode="Opaque" backcolor="#F0F8FF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <style name="Table_CH" mode="Opaque" backcolor="#BFE1FF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <style name="Table_TD" mode="Opaque" backcolor="#FFFFFF">
        <box>
            <pen lineWidth="0.5" lineColor="#000000"/>
            <topPen lineWidth="0.5" lineColor="#000000"/>
            <leftPen lineWidth="0.5" lineColor="#000000"/>
            <bottomPen lineWidth="0.5" lineColor="#000000"/>
            <rightPen lineWidth="0.5" lineColor="#000000"/>
        </box>
    </style>
    <subDataset name="TicketDataSet" uuid="af87285f-3ee2-454d-8102-313d6ab38914">
        <parameter name="headerId" class="java.lang.String"/>
        <parameter name="headerSubject" class="java.lang.String"/>
        <parameter name="headerProject" class="java.lang.String"/>
        <parameter name="headerType" class="java.lang.String"/>
        <parameter name="headerDuration" class="java.lang.String"/>
        <queryString>
            <![CDATA[]]>
        </queryString>
        <field name="id" class="java.lang.Integer"/>
        <field name="subject" class="java.lang.String"/>
        <field name="fileName" class="java.lang.String"/>
        <field name="typeName" class="java.lang.String"/>
        <field name="workMinutes" class="java.lang.Integer"/>
    </subDataset>
    <parameter name="headerId" class="java.lang.String"/>
    <parameter name="headerSubject" class="java.lang.String"/>
    <parameter name="headerProject" class="java.lang.String"/>
    <parameter name="headerType" class="java.lang.String"/>
    <parameter name="headerDuration" class="java.lang.String"/>
    <parameter name="ticketsDataSource" class="net.sf.jasperreports.engine.data.JRBeanCollectionDataSource"/>
    <field name="Title" class="java.lang.String">
        <fieldDescription><![CDATA[TEST]]></fieldDescription>
    </field>
    <background>
        <band splitType="Stretch"/>
    </background>
    <columnHeader>
        <band height="62" splitType="Stretch">
            <componentElement>
                <reportElement x="170" y="0" width="410" height="62" uuid="ea0d1bc7-20ee-4a73-8e20-82494215b940">
                    <property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.VerticalRowLayout"/>
                    <property name="com.jaspersoft.studio.table.style.table_header" value="Table_TH"/>
                    <property name="com.jaspersoft.studio.table.style.column_header" value="Table_CH"/>
                    <property name="com.jaspersoft.studio.table.style.detail" value="Table_TD"/>
                </reportElement>
                <jr:table xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components http://jasperreports.sourceforge.net/xsd/components.xsd">
                    <datasetRun subDataset="TicketDataSet" uuid="061b061f-f5d5-4892-b3c4-e5b8d85f28a1">
                        <datasetParameter name="headerId">
                            <datasetParameterExpression><![CDATA[$P{headerId}]]></datasetParameterExpression>
                        </datasetParameter>
                        <dataSourceExpression><![CDATA[$P{ticketsDataSource}]]></dataSourceExpression>
                    </datasetRun>
                    <jr:column width="50" uuid="635ee962-de22-4d7e-a89f-395ad81bdb3c">
                        <property name="com.jaspersoft.studio.components.table.model.column.name" value="Column1"/>
                        <jr:tableHeader style="Table_TH" height="30" rowSpan="1">
                            <textField>
                                <reportElement x="0" y="0" width="50" height="30" uuid="c8b56f8c-593a-4c70-98bd-c20ceb88a528"/>
                                <textElement textAlignment="Left"/>
                                <textFieldExpression><![CDATA[$P{headerId}]]></textFieldExpression>
                            </textField>
                        </jr:tableHeader>
                        <jr:detailCell style="Table_TD" height="30">
                            <textField>
                                <reportElement x="0" y="0" width="50" height="30" uuid="32ef7b8c-84cb-4b59-85a9-decfdaf76967"/>
                                <textElement textAlignment="Left"/>
                                <textFieldExpression><![CDATA[$F{id}]]></textFieldExpression>
                            </textField>
                        </jr:detailCell>
                    </jr:column>
                </jr:table>
            </componentElement>
        </band>
    </columnHeader>
    <detail>
        <band height="302" splitType="Stretch">
            <property name="com.jaspersoft.studio.layout" value="com.jaspersoft.studio.editor.layout.spreadsheet.SpreadsheetLayout"/>
        </band>
    </detail>
    <columnFooter>
        <band height="45" splitType="Stretch"/>
    </columnFooter>
</jasperReport>

Answer 1

所以我需要做两件事才能显示子报告:

1. 根据 data67 的建议，我需要在子报表上设置 JREmptyDataSource():
   subreport.setDataSourceExpression(new JRDesignExpression("new net.sf.jasperreports.engine.JREmptyDataSource( )"));

2. 我需要将子报表(在设置所有参数后)插入到主报表的列标题中:
   ((JRDesignBand) jasperDesign.getColumnHeader()).addElement(subreport);