Getting java.lang.IllegalStateException error with response.getOutputStream

Question

Hi,
I am writer a JSP site for displaying JFreeChart. The main JSP page gets some parameters then the second page out put the chart as binary data with a Java class.
I've located the part which generated the error, as follows:
Code:
OutputStream os = response.getOutputStream(); <--- this line cause the error
response.setContentType("image/png");
ChartUtilities.writeChartAsPNG(os, chart, 400, 300);
(other than it, the JSP does nothing with response or out)
Error:
Servlet.service().for servlet jsp threw exception java.lang.IllegalStateException
at org.apache.jasper.runtime.ServletResponseWrapperInclude.getOutputStream(ServletResponseWrapperInclude.java:62)
at org.apache.jsp.build005f005.seriesChart_jsp.jspService(org.apache.jsp.build_005f005.seriesChart_jsp:110)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:99)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWarpper.java:325)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:245)
I've searched this forum and google and seeking for solution for thousands times. But sadly, ways such as adding out.reset(); doesn't work.
Would any one has some suggestion for me? Your help is very appreciated. Thanks!

Answer 1

A similar question / answers from jGuru.com
Question I used getOutputStream() of response object in JSP. Below is the code for download a file in JSP.
%>
<%@ page import="java.util.*,
                    java.io.*"
%>
<%@ page language="java"
          session="false"
          contentType="text/html; charset=8859_1"
%>
<%
     //read the file name.
     File fFile = new File ("D:/Ibs/outdir/batchres.conf");
     String stFileName = "batchres.conf";
     //the content type set as excel
     response.setContentType ("application/excel");
     //the header and also the Nameis set by which user will be prompted to save
     response.setHeader ("Content-Disposition", "attachment;filename=\""+stFileName+"\"");
     //Open an input stream to the file and post the file contents thru the
     //servlet output stream to the client m/c
     InputStream isStream = null;
     ServletOutputStream sosStream = null;
     try
          //response.flushBuffer();
          isStream = new FileInputStream(fFile);
          sosStream = response.getOutputStream();
          int ibit = 256;
          while ((ibit) >= 0)
          ibit = isStream.read();
          sosStream.write(ibit);
     catch (IOException ioeException)
sosStream.flush();
sosStream.close();
isStream.close();
%>
If run this code in Tomcat i am getting following error.. �<h1>Error: 500</h1> <h2>Location: /imu/jsp/ibUTLCmnDownloadView.jsp</h2>Internal Servlet Error:
java.lang.IllegalStateException: getOutputStream() has already been called
     at org.apache.tomcat.facade.HttpServletResponseFacade.getWriter(Unknown Source)
     at org.apache.jasper.runtime.JspWriterImpl.initOut(Unknown Source)
     at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(Unknown Source)
     at jsp.ibUTLCmnDownloadView_12._jspService(ibUTLCmnDownloadView_12.java, Compiled Code)
     at org.apache.jasper.runtime.HttpJspBase.service(Unknown Source)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java)
     at org.apache.tomcat.facade.ServletHandler.doService(Unknown Source)
     at org.apache.tomcat.core.Handler.invoke(Unknown Source)
     at org.apache.tomcat.core.Handler.service(Unknown Source)
     at org.apache.tomcat.facade.ServletHandler.service(Unknown Source)
     at org.apache.tomcat.facade.RequestDispatcherImpl.doForward(Unknown Source)
     at org.apache.tomcat.facade.RequestDispatcherImpl.forward(Unknown Source)
     at JP.co.Hitachi.soft.IBS.Common.Servlet.ibUTLCmnDownloadScrGenServlet.doPost(ibUTLCmnDownloadScrGenServlet.java:75)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java)
     at org.apache.tomcat.facade.ServletHandler.doService(Unknown Source)
     at org.apache.tomcat.core.Handler.invoke(Unknown Source)
     at org.apache.tomcat.core.Handler.service(Unknown Source)
     at org.apache.tomcat.facade.ServletHandler.service(Unknown Source)
     at org.apache.tomcat.core.ContextManager.internalService(Unknown Source)
     at org.apache.tomcat.core.ContextManager.service(Unknown Source)
     at org.apache.tomcat.modules.server.Http10Interceptor.processConnection(Unknown Source)
     at org.apache.tomcat.util.net.TcpWorkerThread.runIt(Unknown Source)
     at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(Unknown Source)
     at java.lang.Thread.run(Thread.java:479)
Answer
Don't know if this will help--your code worked as is on my system (J2SDK 1.4.1, Tomcat 4.1.12, Linux)--but you're setting the content-type twice, and to two different values. In the page directive, you specify contentType="text/html; charset=8859_1", and then in the scriptlet, you do a response.setContentType ("application/excel");. Try changing the one in the page directive and deleting the one in the scriptlet. The servlet container may be calling getOutputStream() when it sees the text MIME type so it can prepare the out built-in variable.
Also, according to the J2EE design patterns, JSP's should only be used to produce text output. Any binary output (such as Excel files) should be produced with servlets--otherwise, the JSP becomes one big scriptlet (like this one).
If you still want to do this with a JSP, you might want to take out your try ... catch block since you're not doing anything with it. Doing so will allow you to let the servlet container handle the errors (i.e. specify error pages in the web application deployment descriptor). Either that, or at least put the close() and flush()calls in it since they can throw IOExceptions, too. :)
Finally, you should never close the servlet's output stream. Leave that up to the servlet container.
Is this item helpful? yes no Previous votes Yes: 2 No: 3
To transfer file from client to server using jsp programs
chalpati Rao, Aug 11, 2004 [replies:1]
How to Download File using JSP program
Re: To transfer file from client to server using jsp programs
Saravanan Mani, Aug 24, 2004
Try restarting the server.It worked for me (ie.you did all the code changes mentioned in the previous reply)
Breakline problems
David Machado, Jan 27, 2005 [replies:1]
Hi! Maybe a problem with breaklines. Try this: ------------------------------------------------------
%><%@ // don't send breakline here!!!
page import="java.util.*,
java.io.*"
%><%@ // don't send breakline here too!!!
page language="java"
session="false"
contentType="text/html; charset=8859_1"
%><% // finally, don't send breakline here!!!
//read the file name.
File fFile = new File ("D:/Ibs/outdir/batchres.conf");
String stFileName = "batchres.conf";
//the content type set as excel
response.setContentType ("application/excel"); // twice???
//the header and also the Nameis set by which user will be prompted to save
response.setHeader ("Content-Disposition", "attachment;filename=\""+stFileName+"\"");
//Open an input stream to the file and post the file contents thru the
//servlet output stream to the client m/c
InputStream isStream = null;
ServletOutputStream sosStream = null;
try
//response.flushBuffer();
isStream = new FileInputStream(fFile);
sosStream = response.getOutputStream();
int ibit = 256;
while ((ibit) >= 0)
ibit = isStream.read();
sosStream.write(ibit);
catch (IOException ioeException)
sosStream.flush();
sosStream.close();
isStream.close();
%> // make sure that's no breakline an no spaces at the end!!
Re: Breakline problems
Aarthi Sivaram, Apr 19, 2005
In the above code sosStream = response.getOutputStream(); must be removed. Use 'out' instead of sosStream i.e. out.write(""+ibit); If you look at the Java code generated for your JSP, you can find JspWriter out = null ... .. JspWriter calls response.getOutputStream(), thats why when u call getOutputStream, u get IllegalStateException. 'out' variable is available for direct use in all JSP's, like 'request'. So that can be directly used to write.
A quick and working workaround
Leslie Leng, May 20, 2005 [replies:1]
I am not going to discuss the theory behind, as others gurus mentioned before me, are valid.
In short, getOutputStream() could not be used more than once, and also it will conflict with JSPWriter's out.
So, the quick workaround would be, at the end of the JSP page, add the following:
out.clear();
out = pageContext.pushBody();
in example:
catch(Exception e){
System.out.print(e);
out.clear();
out = pageContext.pushBody();
%>
Re: A quick and working workaround
ajit Pandey, Jul 15, 2005
Thanks a ton Leslie ,it worked(Production issue) :) credit goes to you....indebted