File is Not Displaying

I am having two problems with this. First my file will not display, second I get a System Out Error. Please help.

[11/6/08 14:38:01:891 CST] 00000033 ServletWrappe E SRVE0068E: Could not invoke the service() method on servlet ViewDrawing6. Exception thrown : java.lang.IllegalStateException: SRVE0199E: OutputStream already obtained

protected void doGet(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException {
HttpSession session = arg0.getSession(true);

String resultString = "";
String p1 = arg0.getParameter("p1");
   
URL url = new URL ( p1 );

if(session.getAttribute("pendingA") == "true"){

resultString = "{errorString: 'Pending A Revisions have no viewable drawing until released!'}";

}
else if(url.openConnection().getContentLength() > 4040){

ServletOutputStream out = arg1.getOutputStream();
arg1.setContentType( "application/pdf" ); 
arg1.setHeader("Content-Disposition", "attachment");

BufferedInputStream  bis = null;
BufferedOutputStream bos = null;
    
try {
bis = new BufferedInputStream(url.openStream());
    
bos = new BufferedOutputStream(out);
byte[] buff = new byte[2048];
int bytesRead; 
while(-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff, 0, bytesRead);
}

}
finally {
if (bis != null) bis.close();  // very important
if (bos != null) bos.close();  // very important
}
 
// finish up
out.println("</body></html>");
resultString = "{errorString: 'NoError'}";

}
else{

resultString = "{errorString: 'No PDF file could be found!'}";

}

arg1.getWriter().write(resultString);

}

You are calling both getOutputStream and getWriter. Also, what's with emitting the trailing html closing tags? This code looks very suspect.

Originally posted by Bear Bibeault:
You are calling both getOutputStream and getWriter.

How do I fix this part?

Originally posted by Bear Bibeault:
Also, what's with emitting the trailing html closing tags? This code looks very suspect.

I don't really understand this comment.

Do any of these have anything to do with the file not displaying?

Originally posted by Steve Dyke:
How do I fix this part?

Easy. Don't do that. Fetch the response stream as either an output stream or a writer; not both.

I don't really understand this comment.

The code is useless and superfluous. What is it doing there? You're not emitting HTML, so why the needless output?
[ November 06, 2008: Message edited by: Bear Bibeault ]

Originally posted by Bear Bibeault:
Easy. Don't do that. Fetch the response stream as either an output stream or a writer; not both.

[ November 06, 2008: Message edited by: Bear Bibeault ]

Okay, so how do I use this servlet response to write a file for display and then write a response back to my calling jQuery.getJSON call?

You don't. You can't return two responses to a single request.

You're going to need to back up and explain what it is that you are really trying to accomplish.

On my JSP I have a function that uses a jQuery.getJSON call to the servlet sending a url address as a parameter. It is supposed to display a drawing cooesponding to the url. If the url does not exist I want to return a flag to the calling JSP and display a message to that effect. If the url does exist I want to display the drawing. Right now the servlet code rus but no drawing is displayed.

getJSON expects you to return JSON. It looks like you are trying to return a PDF.

Okay, I changed to jQuery.post and it still will not work.

This will work if I put it directly in the link code

This will not work if in the link code I have href="javascript:viewdrawing()"

and viewdrawing() is

What would be the difference?

You can't return a drawing in an Ajax request.

From what you said, here's what I'd suggest:

Your Ajax request hits a servlet that checks if the drawing exists

If it does not, it returns JSON error info

If it does, it returns JSON that contains the URL of another servlet that will stream the PDF

The client takes that URL, and uses it to display the drawing in another window or iframe

Thanks. It works great.

I got same exception as

Exception thrown : java.lang.IllegalStateException: SRVE0199E: OutputStream already obtained

my code is

Exception arises only when code start executing JSP page.

Could you please help?

Your code is not complete, but I suspect you're doing exactly what your exception message says. Trying to write multiple responses to one request. Are you using a RequestDispatcher to talk to a JSP after writing to the OutputStream?

What a JSP does is basically make an HTML page and write it to the response object. If you've already written to the response object and then you write a whole jsp page... then of course you get that exception. You can't write the response, and then dispatch to a JSP, because you've already written your response!

I am using struts 1.1 , so the execute method return return mapping.findForward("success");

In struts.xml the jsp is defined. when the code starts executing the jsp it gives exception in server log , not in page. Page gets successfully loaded.

Thanks

my jsp code is