to Brian: okay, I think I see what you mean: The BufferedOutputStream is able to read a file only when the file is not being read by any other BufferedOutputStream object at the same time. Generally speaking, when saying an object is synchronized, it usually means that when two threads are trying to invoke this object's methods simultaneously, one thread has to wait untill the other is done - which is not the case here, as two different BufferedOutputStream objects or more are used simultaneously. It is the file itself which is synchronized. get my drift?
to Joe: I'm afraid we're having somewhat of deaf people's conversation here. Read Brian's original post and his response and see what I mean. Thanks for the through explanation anyway... zm. -----Original Message----- From: A mailing list about Java Server Pages specification and reference [mailto:[EMAIL PROTECTED]]On Behalf Of Brian Bohnet Sent: Tuesday, January 15, 2002 11:38 PM To: [EMAIL PROTECTED] Subject: Re: Downloading files with jsp/servlets... Well, Zvika, according to my team, the file requested for download was being locked by using BufferedOutputStream(being synchronized by default), so any other requests for that file were not allowed until the previous request was finished reading/writing to buffer. Hope that helps, Brian Zvika Markfeld wrote: > > but why does the synchronousity prevent simultaneous download? The output > stream gets declared and obtained inside service() method, doesn't it? and > if so, as any other local variable/object, it gets duplicated for each and > every one of the threads that invokes that servlet instance, so there isn't > a common monitor that locks other requests/ Am I missing something here? > Could you please explain that matter? > zm. > > -----Original Message----- > From: A mailing list about Java Server Pages specification and reference > [mailto:[EMAIL PROTECTED]]On Behalf Of Brian Bohnet > Sent: Tuesday, January 15, 2002 12:40 AM > To: [EMAIL PROTECTED] > Subject: Re: Downloading files with jsp/servlets... > > Joe Cheng wrote: > > > > Can you post the servlet code? What servlet container are you using > > (WebLogic, Tomcat...?) > > > > The servlet should absolutely be able to handle two simultaneous requests, > > unless your service method is synchronized. > > > > > =========================================================================== > > To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff > JSP-INTEREST". > > For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST > DIGEST". > > Some relevant FAQs on JSP/Servlets can be found at: > > > > http://archives.java.sun.com/jsp-interest.html > > http://java.sun.com/products/jsp/faq.html > > http://www.esperanto.org.nz/jsp/jspfaq.jsp > > http://www.jguru.com/faq/index.jsp > > http://www.jspinsider.com > > Well we have figured out a solution. Since the BufferedOutputStream is > synchronized, only one request had access to the file object at one time > so, we wrote a new class that is very similar to BufferedOutputStream. > This new class relies on the operating system to delegate bandwidth and > thread the simultaneous processes for the same file, allowing > asynchronous downloads from the same servlet. > The servlet passes the responsibility on to the new class to handle the > reading/writing of the file contents. Also, during testing we had 5 > requests for the same file occur, and all five began and ended > downloading a 56M file within seconds of each other and all with equally > balanced bandwidth on Dell servers running linux7.1 using Apache/Tomcat > configuration. > > Thanks for your response. > Brian > > =========================================================================== > To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff > JSP-INTEREST". > For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST > DIGEST". > Some relevant FAQs on JSP/Servlets can be found at: > > http://archives.java.sun.com/jsp-interest.html > http://java.sun.com/products/jsp/faq.html > http://www.esperanto.org.nz/jsp/jspfaq.jsp > http://www.jguru.com/faq/index.jsp > http://www.jspinsider.com > > =========================================================================== > To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". > For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". > Some relevant FAQs on JSP/Servlets can be found at: > > http://archives.java.sun.com/jsp-interest.html > http://java.sun.com/products/jsp/faq.html > http://www.esperanto.org.nz/jsp/jspfaq.jsp > http://www.jguru.com/faq/index.jsp > http://www.jspinsider.com =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
