最近正在做一个基于J2EE的Web项目,使用IReport与JasperReport作为Web报表的解决方案,在使用Html报表形式进行打印时出现如下问题。(同样的问题使用了不同的解决方法)
一.问题描述:使用JasperReport生成Html报表后,数据显示正确,但各种线条显示不出来
产生原因:在生成HTML页面时JRHtmlExporterParameter.IMAGES_URI参数设置不正确,主要是图片的路径问题。由JasperReport生成Html时,那些线条是一个名称为px像素的图片,是内置在jasperreports包中的,在IE显示时以图片的形式显示
解决办法:查阅了网络许多资料,照其方法测试均未解决。无奈之下,查看JasperReport的源代码才搞定。
1、在web.xml中添加如下配置:
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>net.sf.jasperreports.j2ee.servlets.ImageServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/servlets/image</url-pattern>
</servlet-mapping>
2、在调用程序中增加如下代码:
exporter.setParameter(JRHtmlExporterParameter.IMAGES_URI, request.getContextPath()+"/servlets/image?image=");
全部调用程序如下:
<%@ page contentType="application/pdf;charset=GB2312"%>
<%@ page import="net.sf.jasperreports.engine.*" %>
<%@ page import="net.sf.jasperreports.engine.util.*" %>
<%@ page import="net.sf.jasperreports.engine.export.*" %>
<%@ page import="net.sf.jasperreports.j2ee.servlets.*" %>
<%@ page import="java.util.*" %>
<%@ page import="java.io.*" %>
<%@ page import="java.sql.*" %>
<%
// "/reports/test.jasper"是ireport编译后的报表文件
File reportFile = new File(application.getRealPath("/reports/test.jasper"));
if(!reportFile.exists())
throw new JRRuntimeException("报表绘制失败,找不到报表配置文件!");
JasperReport jasperReport = (JasperReport)JRLoader.loadObject(reportFile.getPath());
String url ="jdbc:jtds:sqlserver://127.0.0.1/test";
Class.forName("net.sourceforge.jtds.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection(url,"sa", "");
//null为无参数传入
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, null, conn);
JRHtmlExporter exporter = new JRHtmlExporter();
StringBuffer sbuffer = new StringBuffer();
session.setAttribute(ImageServlet.DEFAULT_JASPER_PRINT_SESSION_ATTRIBUTE, jasperPrint);
exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
exporter.setParameter(JRExporterParameter.OUTPUT_WRITER, out);
exporter.setParameter(JRHtmlExporterParameter.IMAGES_URI, request.getContextPath()+"/servlets/image?image=");
exporter.exportReport();