Equivalent of JSF's responseComplete() in Spring Webflow

[chandru.in]

I'm just not very fluent with Spring MVC as I'm
with JSF. In one of our organization's projects, we use Spring MVC and use
Jasper for reproting. We allow users to download a .PDF report. In JSF,
after writing the PDF bytes to the response stream along with
Content-Disposition header, I invoke responseComplete() on FacesContext
instance to tell JSF not to meddle with the reponse further.

How do I achieve the same with Spring MVC?

Right now we get a,

java.lang.IllegalStateException
        at org.apache.catalina.connector.ResponseFacade.sendRedirect(ResponseFac
ade.java:435)

[Rossen Stoyanchev]

Spring MVC has built-in support for Jasper. Have a look at the Spring reference documentation. Also one of the samples that ship with the framework demonstrate how to do this.

[arpan]

I tried the same in Spring webflow. I am using Jasperreport to generate a PDF. But downloading the PDF creates a problem in this approach.

My code snippet looks like below..

Code :
private void generatePdf(String path, RequestContext requestContext)
throws IOException
{
ServletExternalContext servletExternalContext =
(ServletExternalContext)requestContext.getExternal Context();
HttpServletResponse response =
(HttpServletResponse)servletExternalContext.getNat iveResponse();
....
....
response.setContentType("application/pdf");
byte[] bytes = JasperExportManager.exportReportToPdf(print);
response.setContentType("application/pdf");
response.setHeader("Content-disposition", "attachment; filename=\""
+ OUTPUT_FILE_NAME);
response.setContentLength(bytes.length);
ServletOutputStream servletOutputStream = response.getOutputStream();
servletOutputStream.write(bytes);
servletOutputStream.flush();
}


But in this way I get some error and the downloaded PDF does not open. The error which I get is like below...(I tried the same without flushing the outputStream but landed with the same.)

11:57:28,297 ERROR [[jsp]] Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for t
his response

I think I am getting this error because Framework still tries to call getOutputStream() to complete the response. But I have no idea how can I stop that and handle the response manually. (If any handling required furthermore).

Can anyone help me about this? I guess this problem is relevant to the problem stated above.

[shiv12]

Hi,

I am doing a similar thing like this..When i am calling a method like this from my flow.xml an error is coming..
can u please post how u r calling the method from flow

[arpan]

Hi,

There is nothing unusual in the flow according to me. I am calling using webflow:evaluate to execute. Please refer the code below for reference.

<webflow:view-state id="view" view="view">
<webflow:transition on="generatePdf">
<webflow:evaluate
expression="pdfGenerationFormAction.exportAsPdf">
</webflow:evaluate>
</webflow:transition>
</webflow:view-state>

exportAsPdf(RequestContext) is the method which calls the generatePdf() method intern.

Any thing wrong in this part?

[shiv12]

Hi,

I am also trying to call a method like this.
But the problem is that its searching for the method as methodname not as methodname(requestContext)

for my code details please check:
http://forum.springframework.org/showthread.php?t=67552
http://forum.springframework.org/showthread.php?t=67456

[rsood]

Did anyone find a solution to this problem ..since I am also having a similar problem

[indybubble]

Has anyone found a solution to the issue with?

I'm also having the same problem

java.lang.IllegalStateException: getOutputStream() has already been called for this response when trying the example with:

<transition on="print">
        <evaluate expression="printBoardingPassAction" />
    </transition>

[migelct1983]

In the action method:

import org.springframework.webflow.execution.RequestContext;

public print(RequestContext context) {

    //generate the file ... and in the end
    context.getExternalContext().recordResponseComplete();
}