Problem in drawing image on the fly using jsp

Question

I have been searching the forum and web for the problem but in vain. I have wrote a jsp which creates an image on the fly from the data selected from the database. But after the image is drawn, it throws an IllegalStateException. The offending code is at the time of releasePageContext() method of the compiled jsp. I am using the following code in jsp to display the image.
BufferedImage bi = obj.getBufferedImage();
javax.imageio.ImageIO.write(bi,"png",response.getOutputStream());
I even tried to do the same with servlet, but the problem is that when I am using forward action in jsp I am getting the image but the control is in the servlet and if I am including the servlet, I am getting junk characters instead of image. I have set the content type in servlet and also in jsp.
Thank you in advance.

Answer 1

Hi all,
I've developed a web application using glassfish server... my database is postgresql.... i try to generate a report using Jasper Reports.... i've succesfully developed the report template..... My problem when ever i try to generate a report it gets the data from the back end.... and throws the following error.....
StandardWrapperValve[jsp]: Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.coyote.tomcat5.CoyoteResponse.getWriter(CoyoteResponse.java:652)
at org.apache.coyote.tomcat5.CoyoteResponseFacade.getWriter(CoyoteResponseFacade.java:196)
at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:149)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:142)
at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:216)
at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:134)
at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:89)
at org.apache.jsp.GenerateBirthCertificate_jsp._jspService(GenerateBirthCertificate_jsp.java:149)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:353)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:409)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:317)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:397)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:278)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:179)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:73)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:182)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at com.sun.enterprise.web.VirtualServerPipeline.invoke(VirtualServerPipeline.java:120)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:137)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:536)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:939)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.invokeAdapter(ProcessorTask.java:667)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.processNonBlocked(ProcessorTask.java:574)
at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:844)
at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:287)
at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:212)
at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:252)
at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:75)
i've written my code in jsp.... My code is....
<%@page contentType="text/html"%>
<%@page pageEncoding="UTF-8"%>
<%@ page language="java" import="java.io.*, net.sf.jasperreports.engine.*, java.sql.*, java.util.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>CDAC Portal</title>
</head>
<body>
<%
try {
Connection con=null;
String query="";
String regNo="";
regNo=request.getParameter("regNo");
regNo = regNo.toUpperCase();
out.println("Registration No :"+regNo);
Class.forName("org.postgresql.Driver");
con = DriverManager.getConnection("jdbc:postgresql://192.168.31.79:5432/Municipality","postgres","");
System.out.println("connected succefully");
ServletContext context = this.getServletConfig().getServletContext();
File reportFile = new File(context.getRealPath("/reports/birth_cert.jasper"));
query="select * from birth_details where regn_unit='"+regNo+"'";
Map parameters = new HashMap();
parameters.put("regNo",""+regNo);
parameters.put("query",""+query);
byte[] bytes = null;
try {               
bytes = JasperRunManager.runReportToPdf(reportFile.getPath(), parameters, con);
response.setContentType("application/pdf");
response.setContentLength(bytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(bytes, 0, bytes.length);
ouputStream.flush();
ouputStream.close();
} catch (JRException e) {
System.out.println("Error : "+e);
con.close();
} catch(Exception exc) {
System.out.println("Connection pool error :"+exc.toString());
%>
</body>
</html>
can anyone help me hw to solve this problem....
Thanks in advance
R Vijay,
Project Engineer,
CDAC, Chennai.
India
[email protected]
[email protected]