Jasper reports 为什么在Jasper Reports中创建空报告

我是Jasper Reports的新手，有人能告诉我为什么在数据库中重新发送数据的情况下创建空报告吗

请看这是我的节目

public class ReportDriver {

    /**
     * Constructor for ReportDriver
     */
    public ReportDriver() {
    }

    public static void main(String args[]) {
        Connection con = null;
        try {

            Class.forName("oracle.jdbc.driver.OracleDriver");

            con = DriverManager.getConnection(
                    "jdbc:oracle:thin:@localhost:1521:orcle", "scott", "tiger");

            JasperDesign jasperDesign = JRXmlLoader
                    .load("C:\\Documents and Settings\\Admin\\report5.jrxml");

            JasperReport jasperReport = JasperCompileManager
                    .compileReport(jasperDesign);

            JasperPrint jasperPrint = JasperFillManager.fillReport(
                    jasperReport, null, con);
            JasperViewer.viewReport(jasperPrint);
        } catch (Exception ex) {
            ex.printStackTrace();
            String connectMsg = "Could not create the report ";
            System.out.println(connectMsg);
        }
    }

}
This is my jrxml file 

<?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="report5" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20">
    <queryString language="SQL">
        <![CDATA[select EMPNO , ENAME ,  JOB from emp]]>
    </queryString>
    <field name="EMPNO" class="java.math.BigDecimal"/>
    <field name="ENAME" class="java.lang.String"/>
    <field name="JOB" class="java.lang.String"/>
    <background>
        <band splitType="Stretch"/>
    </background>
    <title>
        <band height="79" splitType="Stretch"/>
    </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>

公共类ReportDriver{
/**
*ReportDriver的构造函数
*/
公共报告驱动程序（）{
}
公共静态void main（字符串参数[]）{
连接con=null；
试一试{
类forName（“oracle.jdbc.driver.OracleDriver”）；
con=DriverManager.getConnection(
“jdbc:oracle:thin:@localhost:1521:orcle”、“scott”、“tiger”）；
JasperDesign JasperDesign=JRXmlLoader
.load（“C:\\Documents and Settings\\Admin\\report5.jrxml”）；
JasperReport JasperReport=JasperCompileManager
.compileReport（jasperDesign）；
JasperPrint JasperPrint=JasperFillManager.fillReport(
jasperReport，空，con）；
JasperViewer.viewReport（jasperPrint）；
}捕获（例外情况除外）{
例如printStackTrace（）；
String connectMsg=“无法创建报告”；
System.out.println（connectMsg）；
}
}
}
这是我的jrxml文件

您的报告是空的，因为它应该是空的：您的jrxml不包含任何要显示的元素。尝试以下jrxml并查看其区别：

<?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="report5" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20">
    <queryString language="SQL">
        <![CDATA[select EMPNO , ENAME ,  JOB from emp]]>
    </queryString>
    <field name="EMPNO" class="java.math.BigDecimal"/>
    <field name="ENAME" class="java.lang.String"/>
    <field name="JOB" class="java.lang.String"/>
    <background>
        <band splitType="Stretch"/>
    </background>
    <title>
        <band height="79" splitType="Stretch"/>
    </title>
    <pageHeader>
        <band height="35" splitType="Stretch"/>
    </pageHeader>
    <columnHeader>
        <band height="61" splitType="Stretch"/>
    </columnHeader>
    <detail>
        <band height="125" splitType="Stretch">
            <textField>
                <reportElement x="0" y="0" width="100" height="20"/>
                <textElement/>
                <textFieldExpression class="java.lang.String"><![CDATA[$F{EMPNO}]]></textFieldExpression>
            </textField>
            <textField>
                <reportElement x="0" y="20" width="100" height="20"/>
                <textElement/>
                <textFieldExpression class="java.lang.String"><![CDATA[$F{ENAME}]]></textFieldExpression>
            </textField>
            <textField>
                <reportElement x="0" y="40" width="100" height="20"/>
                <textElement/>
                <textFieldExpression class="java.lang.String"><![CDATA[$F{JOB}]]></textFieldExpression>
            </textField>
        </band>
    </detail>
    <columnFooter>
        <band height="45" splitType="Stretch"/>
    </columnFooter>
    <pageFooter>
        <band height="54" splitType="Stretch"/>
    </pageFooter>
    <summary>
        <band height="42" splitType="Stretch"/>
    </summary>
</jasperReport>