If servlet is secure and trys to do:

if (fromFile.exists() && !fromFile.isDirectory()) {
      	    byte[] buf = new byte[100*1024];
      	    //Set header and mime type
      	    String mimetype = downloadConfig.getServletContext().getMimeType( 
fileName );
      	    response.setContentType( (mimetype != null) ? 
mimetype : "application/octet-stream" );
            response.setContentLength( (int)fromFile.length() );
            response.setHeader( "Content-Disposition", "attachment; 
filename=\"" + request.getParameter("file") + "\"" );
      	    BufferedInputStream bufIS = new BufferedInputStream(new 
FileInputStream(fromFile),1024*1024);
      	    int byteRead;
      	    ServletOutputStream out = response.getOutputStream();
      	    while( (bufIS != null) && (byteRead = bufIS.read(buf,0,100*1024)) !
= -1) {
      	      out.write(buf,0,byteRead);
      	    }
      	    bufIS.close();
      	    out.flush();      	    
      	    out.close();

than output is ok only first time. Any other attempt to do it arise the socket 
error and put in log file:

2002-03-13 17:47:02 [org.apache.catalina.connector.warp.WarpConnector] Error 
accepting requests
java.net.SocketException: socket closed
	at java.net.PlainSocketImpl.socketAccept(Native Method)
	at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:468)
	at java.net.ServerSocket.implAccept(ServerSocket.java:243)
	at java.net.ServerSocket.accept(ServerSocket.java:222)
	at org.apache.catalina.connector.warp.WarpConnector.run
(WarpConnector.java:590)
	at java.lang.Thread.run(Thread.java:484)