Java Swing中的JasperReport PDF输出

Question

在当前的项目中，我正在处理一些Jasper报告。 我有一个包含2个子报告的报告。 我将其导出为pdf文件。 如果我导出的普通jasper报表没有任何子报表，则pdf文件运行正常，当我有子报表时，pdf文件为空白。 以下是我的代码：

static String reportPath = "D:/Netbeans Projects/Abc/mail_reports/";
public static void getReport() {
    try {
        String reportName = reportPath + "AuctionSale/AuctionSeller/AuctionSeller.jasper";
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("sale_date", "2012-01-10");
        JasperPrint jasperPrint = JasperFillManager.fillReport(reportName, params, DB.getConn());
        OutputStream output = new FileOutputStream(new File("C:/JasperReport.pdf")); 
        JasperExportManager.exportReportToPdfStream(jasperPrint, output); 
    } catch (Exception e) {
        e.printStackTrace();
    }
}

有人可以告诉我我在哪里想念，或者我需要做什么才能使报告生效。

谢谢

Answer 1

我可以从以下代码获得打印结果：

String s = Dashboard.mail_seller.getSelectedItem().toString();
            String selected[] = s.split(" -- ");
            String seller_id = selected[0].trim();
            String filename = sale_date + "_" + selected[1].replaceAll(" ", "_").trim() + ".pdf";
            String reportName = reportPath + "AuctionSale/AuctionSellerMail/AuctionSeller.jasper";
            Map<String, Object> params = new HashMap<String, Object>();
            params.put("sale_date", sale_date);
            params.put("seller_id", seller_id);
            JasperPrint jasperPrint = JasperFillManager.fillReport(reportName, params, DB.getConn());
            OutputStream output = new FileOutputStream(new File("D:/Netbeans Projects/JDSons/mail_reports/"+filename+"")); 
            JasperExportManager.exportReportToPdfStream(jasperPrint, output); 
            output.flush();
            output.close();

多谢你们

Answer 2

从该示例或%jasperreports%\\demo\\samples\\subreport文件夹（来自JasperReports分发包）中的完整示例中可以看到，您可以将已编译的子报表作为参数传递。

示例Java代码：

JasperReport subreport = (JasperReport) JRLoader.loadObjectFromFile("build/reports/ProductReport.jasper");

Map parameters = new HashMap();
parameters.put("ProductsSubreport", subreport);

JasperFillManager.fillReportToFile("build/reports/MasterReport.jasper", parameters, getDemoHsqldbConnection());

MasterReport jrxml文件中的代码段：

<parameter name="ProductsSubreport" class="net.sf.jasperreports.engine.JasperReport"/>
...
<detail>
    ...
        <subreport>
            <reportElement isPrintRepeatedValues="false" x="5" y="25" width="325" height="20" isRemoveLineWhenBlank="true" backcolor="#ffcc99"/>
            <subreportParameter name="City">
                    <subreportParameterExpression><![CDATA[$F{City}]]></subreportParameterExpression>
            </subreportParameter>
            <connectionExpression><![CDATA[$P{REPORT_CONNECTION}]]></connectionExpression>
            <returnValue subreportVariable="PriceSum" toVariable="ProductTotalPrice" calculation="Sum"/>
            <subreportExpression class="net.sf.jasperreports.engine.JasperReport"><![CDATA[$P{ProductsSubreport}]]></subreportExpression>
        </subreport>
        <subreport>
            <reportElement positionType="Float" x="335" y="25" width="175" height="20" isRemoveLineWhenBlank="true" backcolor="#99ccff"/>
            <subreportParameter name="City">
                    <subreportParameterExpression><![CDATA[$F{City}]]></subreportParameterExpression>
            </subreportParameter>
            <connectionExpression><![CDATA[$P{REPORT_CONNECTION}]]></connectionExpression>
            <returnValue subreportVariable="REPORT_COUNT" toVariable="CityAddressCount"/>
            <subreportExpression class="java.lang.String"><![CDATA["AddressReport.jasper"]]></subreportExpression>
        </subreport>
</detail>