SWF, JSF, WAS, download file, Out Of Memory

[ramius]

I am using WAS 6.1 App Server, Spring 3.0.3, SWF 2.1.1, JSF 1.2 and facelets. I hava a big problem with download files (pdf or zip/rar). When I download large files, I receive Out Of Memory error (max heap size: 1024MB). I used JProfiler tool and there was more than 700MB allocated to byte[].
My code:

SWF:

<view-state id="test" view="test.xhtml">
     <transition on="download" to="download" />
</view-state>
  	
<action-state id="download">
    <evaluate expression="downloadService.downloadFile(listFiles.selectedRow.file.path)" />
    <transition on="ok" to="test" />
    <transition on="fileNotFound" to="test">
  	<set name="flashScope.message" value="resourceBundle.noFiles" />
    </transition>
</action-state>

Java code:

public String downloadFile(String path){
try{
     ExternalContext externalContext = ExternalContextHolder.getExternalContext();
     HttpServletResponse response = (HttpServletResponse) externalContext.getNativeResponse();
     File file = new File(path);
     FileInputStream in = new FileInputStream(file);
     ServletOutputStream out = response.getOutputStream();
     response.setHeader("Content-Disposition","attachment; filename=\"" +      filename +"\" ");
     response.setHeader("Content-Type", "application/octet-stream");   
     response.setHeader("Content-Length", String.valueOf(file.length()));

     FileCopyUtils.copy(in, out);
     externalContext.recordResponseComplete();
     return "ok";
}
catch(FileNotFoundException fnf){
 return "fileNotFound"
}

Any suggestions to resolve this problem?