如何使用列表在Java Web应用程序中生成PDF子报表？

Question

I'm generating reports with lists and parameters, no database, no query. I'm working with JasperSoft Studio 6 (jasperreports-6.5.1.jar, iText-2.1.7.js2.jar), Eclipse, JSP, Java 7 and Tomcat 7.

I can generate a simple list like this:

Sample.java

public class Sample {
    private String value;
    public Sample(String value) {this.value = value;}
    public String getValue() {return value;}
}

SampleServlet.java

public class SampleServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        try {
            InputStream jrxml = getServletContext().getResourceAsStream("WEB-INF/pdf/Sample.jrxml");
            JasperReport report = JasperCompileManager.compileReport(jrxml);
            List<Sample> list = Arrays.asList(new Sample("One"), new Sample("Two"), new Sample("Three"));
            JRBeanCollectionDataSource source = new JRBeanCollectionDataSource(list);
            JasperPrint print = JasperFillManager.fillReport(report, null, source);
            response.setContentType("application/pdf");
            ServletOutputStream output = response.getOutputStream();
            JRPdfExporter exporter = new JRPdfExporter();
            exporter.setExporterInput(new SimpleExporterInput(print));
            exporter.setExporterOutput(new SimpleOutputStreamExporterOutput(output));
            exporter.exportReport();
        } catch (JRException e) {
            e.printStackTrace();
        }
    }
}

Sample.jrxml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.5.1.final using JasperReports Library version 6.5.1  -->
<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="Blank_A4" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="ec148bc4-3203-4f96-94ac-2c16820bcfb3">
    <queryString>
        <![CDATA[]]>
    </queryString>
    <field name="value" class="java.lang.String"/>
    <detail>
        <band height="32" splitType="Stretch">
            <textField>
                <reportElement x="0" y="0" width="555" height="32" uuid="c0ccbbff-6099-4565-91f2-53e78f7b97be"/>
                <textFieldExpression><![CDATA[$F{value}]]></textFieldExpression>
            </textField>
        </band>
    </detail>
</jasperReport>

This outputs a PDF with a list (each line could be a separate page):

One

Two

Three

---

But I need to add sublists (subreports) in there...

List<Sample> list = Arrays.asList(new Sample("One:"), new Sample("Two:"), new Sample("Three:"));
List<List<SubSample>> sublists = Arrays.asList(
    Arrays.asList(new SubSample("First"), new SubSample("Single"), new SubSample("Solo")),
    Arrays.asList(new SubSample("Second"), new SubSample("Double"), new SubSample("Duo")),
    Arrays.asList(new SubSample("Third"), new SubSample("Triple"), new SubSample("Trio"))
);

...that should output a PDF like this (each group could be a separate page):

One:
First
Single
Solo

Two:
Second
Double
Duo

Three:
Third
Triple
Trio

How can I achieve this?

Answer 1

I got it. Everything's done in the main report, you do nothing at all to the subreport.

Being so, the changes are:

• A copy of Sample.java as SubSample.java and Sample.jrxml as SubSample.jrxml ;
• In Sample.java, a new field List<SubSample> sublist ;
• In SampleServlet.java, the new field filled and a new parameter subreport set as the path for the compiled SubSample.jrxml (.jasper);
• In Sample.jrxml, a new Field java.util.List sublist and a new Parameter java.lang.String subreport ;
• And a second Detail band with a new Subreport element set with its Expression as $P{subreport} and Data Source Expression as new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F{sublist}) .

The result:

SubSample.java

Copy of the original Sample.java

SubSample.jrxml

Copy of the original Sample.jrxml (with a different uuid)

Sample.java

public class Sample {
    private String value;
    private List<SubSample> sublist;
    public Sample(String value) {this.value = value;}
    public String getValue() {return value;}
    public List<SubSample> getSublist() {return sublist;}
    public void setSublist(List<SubSample> sublist) {this.sublist = sublist;}
}

Sample.jrxml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.5.1.final using JasperReports Library version 6.5.1  -->
<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="Blank_A4" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="17771092-9052-49a8-8301-28b1bdf97288">
    <parameter name="subreport" class="java.lang.String"/>
    <queryString>
        <![CDATA[]]>
    </queryString>
    <field name="value" class="java.lang.String"/>
    <field name="sublist" class="java.util.List"/>
    <detail>
        <band height="32" splitType="Stretch">
            <textField>
                <reportElement x="0" y="0" width="555" height="32" uuid="c0ccbbff-6099-4565-91f2-53e78f7b97be"/>
                <textFieldExpression><![CDATA[$F{value}]]></textFieldExpression>
            </textField>
        </band>
        <band height="32">
            <subreport>
                <reportElement x="0" y="0" width="555" height="32" uuid="e51bd9df-f1c5-4776-9438-8854461bad2a"/>
                <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F{sublist})]]></dataSourceExpression>
                <subreportExpression><![CDATA[$P{subreport}]]></subreportExpression>
            </subreport>
        </band>
    </detail>
</jasperReport>

SampleServlet.java

public class SampleServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        try {
            InputStream jrxml = getServletContext().getResourceAsStream("WEB-INF/pdf/Sample.jrxml");
            JasperReport report = JasperCompileManager.compileReport(jrxml);

            String subjrxml = getServletContext().getRealPath("WEB-INF/pdf/SubSample.jrxml");
            String subreport = JasperCompileManager.compileReportToFile(subjrxml);
            Map<String, Object> parameters = new HashMap<String, Object>();
            parameters.put("subreport", subreport);
            List<Sample> list = Arrays.asList(new Sample("One:"), new Sample("Two:"), new Sample("Three:"));
            List<List<SubSample>> sublists = Arrays.asList(
                Arrays.asList(new SubSample("First"), new SubSample("Single"), new SubSample("Solo")),
                Arrays.asList(new SubSample("Second"), new SubSample("Double"), new SubSample("Duo")),
                Arrays.asList(new SubSample("Third"), new SubSample("Triple"), new SubSample("Trio"))
            );
            for (int i = 0; i < list.size(); i++)
                list.get(i).setSublist(sublists.get(i));
            JRBeanCollectionDataSource source = new JRBeanCollectionDataSource(list);
            JasperPrint print = JasperFillManager.fillReport(report, parameters, source);

            response.setContentType("application/pdf");
            ServletOutputStream output = response.getOutputStream();
            JRPdfExporter exporter = new JRPdfExporter();
            exporter.setExporterInput(new SimpleExporterInput(print));
            exporter.setExporterOutput(new SimpleOutputStreamExporterOutput(output));
            exporter.exportReport();
        } catch (JRException e) {
            e.printStackTrace();
        }
    }
}

PDF output:

One:
First
Single
Solo

Two:
Second
Double
Duo

Three:
Third
Triple
Trio

Thanks to these resources .