java - 在使用自定义 genericElement 的情况下如何修复 "No generic element handlers found for namepsace"错误？

Question

我正在尝试调整 example jasper 报告将带有 HTML 处理程序的通用元素自定义为带有 PDF 处理程序的示例。但是当我尝试运行

net.sf.jasperreports.engine.JRRuntimeException: No generic element handlers found for namespace http://jasperreports.sourceforge.net/jasperreports/customPDFexpoter.
at net.sf.jasperreports.engine.export.GenericElementHandlerEnviroment.getElementHandler(GenericElementHandlerEnviroment.java:112)
at net.sf.jasperreports.engine.export.JRPdfExporter.exportGenericElement(JRPdfExporter.java:4136)
at net.sf.jasperreports.engine.export.JRPdfExporter.exportElements(JRPdfExporter.java:1290)
at net.sf.jasperreports.engine.export.JRPdfExporter.exportPage(JRPdfExporter.java:1210)
at net.sf.jasperreports.engine.export.JRPdfExporter.exportReportToStream(JRPdfExporter.java:1074)
at net.sf.jasperreports.engine.export.JRPdfExporter.exportReport(JRPdfExporter.java:691)
at com.jaspersoft.studio.editor.preview.actions.export.AExportAction.exportWithProgress(AExportAction.java:223)
at com.jaspersoft.studio.editor.preview.actions.export.AExportAction.doPreview(AExportAction.java:347)
at com.jaspersoft.studio.editor.preview.actions.export.AExportAction$3.run(AExportAction.java:191)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

我也关注了这个 example如何将 Controller 嵌入 PDF，但没有成功。也找不到 namespace 。我是否遗漏了项目配置中的某些内容？

这是我的 JRXML:

<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.14.0.final using JasperReports Library version 6.14.0-2ab0d8625be255bf609c78e1181801213e51db8f  -->
<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="c685fd77-7e9f-4762-9a4a-422d1c15aed0">
    <property name="com.jaspersoft.studio.data.defaultdataadapter" value="One Empty Record"/>
    <queryString>
        <![CDATA[]]>
    </queryString>
    <background>
        <band splitType="Stretch"/>
    </background>
    <title>
        <band height="500" splitType="Stretch">
            <property name="com.jaspersoft.studio.unit.height" value="px"/>
            <genericElement>
                <reportElement x="94" y="93" width="236" height="107" uuid="0dbdbc2d-cead-47eb-8605-e18cc325259a"/>
                <genericElementType namespace="http://jasperreports.sourceforge.net/jasperreports/customPDFexpoter" name="print"/>
            </genericElement>
        </band>
    </title>
</jasperReport>

我的 jasperreports_extension.properties(在 src 文件夹内)

net.sf.jasperreports.extension.registry.factory.jr.statistics=net.sf.jasperreports.extensions.SpringExtensionsRegistryFactory
net.sf.jasperreports.extension.jr.statistics.spring.beans.resource=com/test/beans.xml

beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">
<bean id="pdfExportHandlerBundle" 
        class="net.sf.jasperreports.engine.export.DefaultElementHandlerBundle">
    <property name="namespace" value="http://jasperreports.sourceforge.net/jasperreports/customPDFexpoter"/>
    <property name="elementHandlers">
        <map>
            <entry key="print">
                <map>
                    <entry key="net.sf.jasperreports.pdf">
                        <ref bean="basePdfExportHandler"/>
                    </entry>
                </map>
            </entry>
        </map>
    </property>
</bean>
<bean id="basePdfExportHandler" class="com.test.TestPDFHandler"
        abstract="true">
</bean>

Java 文件 (src/com/test)

package com.test;

import net.sf.jasperreports.engine.JRGenericPrintElement;
import net.sf.jasperreports.engine.JRPropertiesMap;
import net.sf.jasperreports.engine.JRRuntimeException;
import net.sf.jasperreports.engine.export.GenericElementHandler;
import net.sf.jasperreports.engine.export.GenericElementHandlerBundle;
import net.sf.jasperreports.engine.export.GenericElementPdfHandler;
import net.sf.jasperreports.engine.export.JRPdfExporter;
import net.sf.jasperreports.engine.export.JRPdfExporterContext;
import net.sf.jasperreports.extensions.ExtensionsRegistry;
import net.sf.jasperreports.extensions.ExtensionsRegistryFactory;
import net.sf.jasperreports.extensions.SingletonExtensionRegistry;

import com.lowagie.text.Chunk;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Element;
import com.lowagie.text.Phrase;
import com.lowagie.text.pdf.ColumnText;
import com.lowagie.text.pdf.PdfAction;

public class TestPDFHandler implements GenericElementPdfHandler {

@Override
public boolean toExport(JRGenericPrintElement element) {
    return true;
}

@Override
public void exportElement(JRPdfExporterContext exporterContext,
        JRGenericPrintElement element) {
    Phrase phrase = new Phrase();
    Chunk chunk = new Chunk("print me");
    chunk.setAction(PdfAction.javaScript("this.print(null,this.pageNum,this.pageNum)", exporterContext.getPdfWriter()));
    phrase.add(chunk);

    ColumnText colText = new ColumnText(exporterContext.getPdfWriter().getDirectContent());
    colText.setSimpleColumn(phrase, 
            element.getX(), 
            exporterContext.getExportedReport().getPageHeight() - element.getY(),
            element.getX() + element.getWidth(), 
            exporterContext.getExportedReport().getPageHeight() - element.getY() - element.getHeight(), 
            0, 
            Element.ALIGN_LEFT);

    try {
        colText.go();
    } catch (DocumentException e) {
        throw new JRRuntimeException(e);
    }

}
/*
@Override
public String getNamespace() {
    return "helloWorld";
}

@Override
public GenericElementHandler getHandler(String elementName, String exporterKey) {
    if (elementName.equals("print") && exporterKey.equals(JRPdfExporter.PDF_EXPORTER_KEY)) {
        return this;
    }
    
    return null;
}

@Override
public ExtensionsRegistry createRegistry(String registryId, JRPropertiesMap properties) {
    return new SingletonExtensionRegistry<GenericElementHandlerBundle>(GenericElementHandlerBundle.class, this);
}*/
}

Answer 1

你需要在 jasperreports_extension.properties add 中将其注册为工厂

net.sf.jasperreports.extension.registry.factory.me=com.test.TestPDFHandler

完成后，您需要实现 TestPDFHandler 中缺少的接口(interface)，并且 getNamespace() 需要与您提供的 namespace 相对应genericElementType*

public class TestPDFHandler implements GenericElementPdfHandler, GenericElementHandlerBundle, ExtensionsRegistryFactory {

    @Override
    public boolean toExport(JRGenericPrintElement element) {
        return true;
    }

    @Override
    public void exportElement(JRPdfExporterContext exporterContext,
            JRGenericPrintElement element) {
        Phrase phrase = new Phrase();
        Chunk chunk = new Chunk("print me");
        chunk.setAction(PdfAction.javaScript("this.print(null,this.pageNum,this.pageNum)", exporterContext.getPdfWriter()));
        phrase.add(chunk);

        ColumnText colText = new ColumnText(exporterContext.getPdfWriter().getDirectContent());
        colText.setSimpleColumn(phrase,
                element.getX(),
                exporterContext.getExportedReport().getPageHeight() - element.getY(),
                element.getX() + element.getWidth(),
                exporterContext.getExportedReport().getPageHeight() - element.getY() - element.getHeight(),
                0,
                Element.ALIGN_LEFT);

        try {
            colText.go();
        } catch (DocumentException e) {
            throw new JRRuntimeException(e);
        }

    }

    @Override
    public String getNamespace() {
        return "http://jasperreports.sourceforge.net/jasperreports/customPDFexpoter";
    }

    @Override
    public GenericElementHandler getHandler(String elementName, String exporterKey) {
        if (elementName.equals("print") && exporterKey.equals(JRPdfExporter.PDF_EXPORTER_KEY)) {
            return this;
        }

        return null;
    }

    @Override
    public ExtensionsRegistry createRegistry(String registryId, JRPropertiesMap properties) {
        return new SingletonExtensionRegistry<GenericElementHandlerBundle>(GenericElementHandlerBundle.class, this);
    }
}

_{*你可以指定任何命名空间，我不会使用 http://jasperreports.sourceforge.net/jasperreports/customPDFexpoter 因为它不是我的域，但要遵循你的代码，它被使用在下面的例子中}