ireport3.1.2结合JFreeChart1.0.10能显示文字，但不显示图片

最新推荐文章于 2022-08-02 16:07:49 发布

最新推荐文章于 2022-08-02 16:07:49 发布 · 203 阅读

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#jfreechart #.net #Java #Struts #VB.NET

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本文介绍如何在IReport3.1.2中集成JFreeChart1.0.10来显示图表，并提供了一个具体的示例代码。该示例包括jrxml文件的配置、自定义Scriptlet类以及报表填充和导出过程。

ireport3.1.2结合JFreeChart1.0.10显示不出图片
先生成jrxml,代码如下：


<?xml version="1.0" encoding="GBK"?>
<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="report name" pageWidth="595" pageHeight="842" columnWidth="535" leftMargin="20" rightMargin="20" topMargin="20" 
scriptletClass="com.todaysoft.openflex4j.security.producefunction.jasper.JFreeChartScriptlet" bottomMargin="20">
	<property name="ireport.scriptlethandling" value="2" />
	<property name="ireport.encoding" value="GBK" />
	<import value="java.util.*" />
	<import value="net.sf.jasperreports.engine.*" />
	<import value="net.sf.jasperreports.engine.data.*" />
<variable name="chart" class="net.sf.jasperreports.engine.JRRenderable"/>
	<background>
		<band/>
	</background>
	<title>
		<band height="58">
			<staticText>
				<reportElement x="90" y="12" width="298" height="35"/>
				<textElement textAlignment="Center">
					<font fontName="宋体" size="14" isBold="true"/>
				</textElement>
				<text><![CDATA[在Jasperreport中添加Jfreechart图形]]></text>
			</staticText>
		</band>
	</title>
	<pageHeader>
		<band/>
	</pageHeader>
	<columnHeader>
		<band/>
	</columnHeader>
	<detail>
		<band height="300">
			<image>
				<reportElement x="0" y="12" width="538" height="288"/>
				<imageExpression class="net.sf.jasperreports.engine.JRRenderable"><![CDATA[$V{chart}]]></imageExpression>
			</image>
		</band>
	</detail>
	<columnFooter>
		<band/>
	</columnFooter>
	<pageFooter>
		<band/>
	</pageFooter>
	<summary>
		<band/>
	</summary>
</jasperReport>

在写生成图片的类，代码哪下:


package com.todaysoft.openflex4j.security.producefunction.jasper;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PiePlot3D;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.util.Rotation;

import net.sf.jasperreports.engine.JRDefaultScriptlet;
import net.sf.jasperreports.engine.JRScriptletException;
import net.sf.jasperreports.renderers.JCommonDrawableRenderer;


public class JFreeChartScriptlet extends JRDefaultScriptlet {
	public void afterReportInit() throws JRScriptletException {
		DefaultPieDataset dataset = new DefaultPieDataset();
		dataset.setValue("Java", 40.2F);
		dataset.setValue("VB", 20.2F);
		dataset.setValue("C/C++", 17.5F);
		dataset.setValue("C#", 22.5F);
		dataset.setValue("Perl", 1.0F);

		JFreeChart chart = ChartFactory.createPieChart3D("各种语言使用率",
				dataset, true, true, false);

		PiePlot3D plot = (PiePlot3D)chart.getPlot();
		plot.setStartAngle(290);
		plot.setDirection(Rotation.CLOCKWISE);
		plot.setForegroundAlpha(0.5f);
		plot.setNoDataMessage("没有可显示的数据");

		this.setVariableValue("chart", new JCommonDrawableRenderer(chart));
	}
}

调用的类，代码如下：


package com.todaysoft.openflex4j.security.producefunction.jasper;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspWriter;

import net.sf.jasperreports.engine.JREmptyDataSource;
import net.sf.jasperreports.engine.JRExporterParameter;
import net.sf.jasperreports.engine.JRRuntimeException;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.export.JRHtmlExporter;
import net.sf.jasperreports.engine.export.JRHtmlExporterParameter;
import net.sf.jasperreports.engine.util.JRLoader;
import net.sf.jasperreports.j2ee.servlets.ImageServlet;

public class JFreeChartApp {
	@SuppressWarnings("deprecation")
	public void export(HttpServletRequest request, JspWriter writer)
			throws IOException, Exception {

		String reportSource;
		reportSource = request.getSession().getServletContext()
				.getRealPath("WEB-INF/jasper/jfreechart.jrxml");
		File parent = new File(reportSource).getParentFile();
		File child = new File(
				parent, "jfreechart.jasper");
		JasperCompileManager.compileReportToFile(reportSource, 
				child.getAbsolutePath());
		// 编译成.jasper文件

		if (!parent.exists())
			throw new JRRuntimeException(".jasper文件找不到，无法编译.");

		JasperReport jasperReport;

		jasperReport = (JasperReport) JRLoader.loadObject(child.getAbsolutePath());

		Map parameters = new HashMap();

		JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport,
				parameters, new JREmptyDataSource());

		// 使用JRHtmlExproter导出Html格式
		JRHtmlExporter exporter = new JRHtmlExporter();

		(request.getSession()).setAttribute(
				ImageServlet.DEFAULT_JASPER_PRINT_SESSION_ATTRIBUTE,
				jasperPrint);

		exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
		exporter.setParameter(JRExporterParameter.OUTPUT_WRITER, writer);
		exporter.setParameter(JRHtmlExporterParameter.IMAGES_URI,
				"../OPENFLEX4J/image?image=");

		exporter.exportReport();
	}
}

JSP页面调用


<%@ page import="com.todaysoft.openflex4j.security.producefunction.jasper.*"%>
<%@ page contentType="text/html; charset=GBK"%>

<%
	JFreeChartApp jfreeChartApp = new JFreeChartApp();
	jfreeChartApp.export(request,out);
%>

运行后，能看到静态文本，但看不到图片，还有乱码，请各位大哥，大姐，指点下
[img]http://huanglppp.iteye.com/upload/attachment/51739/3c8e5574-c83b-3aa4-ab30-081da6d7d06f.bmp[/img]