如何在iReport中使用来自Java的参数传递数据源

Question

我正在尝试传递一个项目列表，它被转换为“JRBeanCollectionDataSource”到iReport中。以下是我的java代码：

主要课程：

package javaapplication1;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import net.sf.jasperreports.engine.JRDataSource;

import net.sf.jasperreports.engine.JREmptyDataSource;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;
public class JavaApplication1 {

    public static void main(String[] args) 
    {
        try {
            /* User home directory location */
            String userHomeDirectory = System.getProperty("user.home");
            /* Output file location */
            String outputFile = userHomeDirectory + File.separatorChar + "JasperTableExample.pdf";

            /* List to hold Items */
            List<Item> listItems = new ArrayList<Item>();

            /* Create Items */
            Item iPhone = new Item();
            iPhone.setName("iPhone 6S");
            iPhone.setPrice(65000.00);

            Item iPad = new Item();
            iPad.setName("iPad Pro");
            iPad.setPrice(70000.00);

            /* Add Items to List */
            listItems.add(iPhone);
            listItems.add(iPad);

            /* Convert List to JRBeanCollectionDataSource */
            JRBeanCollectionDataSource itemsJRBean = new JRBeanCollectionDataSource(listItems);
            JRDataSource dataSource = new JRBeanCollectionDataSource(listItems); 
            /* Map to hold Jasper report Parameters */
            Map<String, Object> parameters = new HashMap<String, Object>();
            parameters.put("ds1", itemsJRBean);

            /* Using compiled version(.jasper) of Jasper report to generate PDF */
            /* Using compiled version(.jasper) of Jasper report to generate PDF */
            //JasperPrint jasperPrint = JasperFillManager.fillReport("resources/newReport.jasper", parameters, new JREmptyDataSource());
            JasperPrint jasperPrint = JasperFillManager.fillReport("C:\\Users\\UPUANNGHARI\\Desktop\\report2.jasper", parameters, new JREmptyDataSource());

            /* outputStream to create PDF */
            OutputStream outputStream = new FileOutputStream(new File(outputFile));
            /* Write content to PDF file */
            JasperExportManager.exportReportToPdfStream(jasperPrint, outputStream);

            System.out.println("File Generated");
        } catch (JRException ex) {
            ex.printStackTrace();
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        }
    }
}

Item.java：     package javaapplication1;

public class Item {

    private String name;
    private Double price;

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public Double getPrice()
    {
        return price;
    }

    public void setPrice(Double price)
    {
        this.price = price;
    }

}

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="report2" language="groovy" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="46d70a50-8fb3-4c45-afa0-3cc939ec618a">
    <property name="ireport.zoom" value="1.0"/>
    <property name="ireport.x" value="0"/>
    <property name="ireport.y" value="0"/>
    <parameter name="ds1" class="net.sf.jasperreports.engine.data.JRBeanCollectionDataSource" isForPrompting="false"/>
    <field name="name" class="java.lang.String"/>
    <background>
        <band splitType="Stretch"/>
    </background>
    <title>
        <band height="79" splitType="Stretch">
            <textField>
                <reportElement x="102" y="32" width="100" height="20" uuid="0bfa36df-afdc-4991-aa40-bc9c411ba90c"/>
                <textFieldExpression><![CDATA[$F{name}]]></textFieldExpression>
            </textField>
        </band>
    </title>
    <pageHeader>
        <band height="35" splitType="Stretch"/>
    </pageHeader>
    <columnHeader>
        <band height="61" splitType="Stretch"/>
    </columnHeader>
    <detail>
        <band height="125" splitType="Stretch"/>
    </detail>
    <columnFooter>
        <band height="45" splitType="Stretch"/>
    </columnFooter>
    <pageFooter>
        <band height="54" splitType="Stretch"/>
    </pageFooter>
    <summary>
        <band height="42" splitType="Stretch"/>
    </summary>
</jasperReport>

在我的iReport中，我只需添加一个参数，将其命名为“ds1”，并将其参数类更改为“net.sf.jasperreports.engine.data.JRBeanCollectionDataSource”。然后我放置一个textField并将其表达式更改为“$ F {name}”。在这里，当我运行它时，我得到一个空值。我认为我在配置iReport方面做得不够。显然我不知道怎么做一个完整的连接。请帮我解决一下我应该解决的问题。提前谢谢。