Hi again, As I said earlier I am new to Servlets and am using a freebie server (for development purposes) with a built-in Servlet-container (vqServer from http://www.vqsoft.com ). This doesn't appear to display any console. I have already done some of the other things you suggested and have been writing out my controlling variables to a text file which I then examined. It was from this text file that I discovered my variables are 'magically' incrementing when my code definitely does not increment them by that amount. It is nearly as though some other part of the program, or a second instance of the Servlet, is interfering with the variable. Although I am new to servlets (and Java in general) I have been programming for a long time so am quite confident there is no other part of the program changing the variables. ??? Any further ideas would be welcomed! Best regards, Billy. -----Original Message----- From: Pierre-Yves Saumont [mailto:[EMAIL PROTECTED]] Sent: 18 September 2001 14:12 To: [EMAIL PROTECTED] Subject: Re: Inconsistent behaviour in Servlet output Hi, Do you mean you are developping without access to the servlet container console? Which servlet container do you use? If you use Tomcat or other container that can run in standalone mode, you should probably install a local copy for testing purpose. If you really can't, you can log debug info and read it from your server. You can do this several ways. You can write the debug info to disk and read it through another servlet, or you can use a database, or you can use a static counter to count requests, or you can simply add a member variable to your servlet. This is the easiest way, although not very reliable, but it should at least give you some info. Just add an int member to your servlet, increment it in the doGet method an display it in the response. This way, you will know if the servlet is called more than once (unless the servlet is unloaded and reloaded by the container). Pierre-Yves -----Message d'origine----- De : A mailing list for discussion about Sun Microsystem's Java Servlet API Technology. [mailto:[EMAIL PROTECTED]]De la part de Graham, Billy Envoy� : mardi 18 septembre 2001 14:24 � : [EMAIL PROTECTED] Objet : Re: Inconsistent behaviour in Servlet output Hi Pierre-Yves, Excuse my ignorance, but how do you get a console window displayed when a servlet is running? I can do this OK with a java application but have never seen a console appear during servlet execution? Thanks, Billy. -----Original Message----- From: Pierre-Yves Saumont [mailto:[EMAIL PROTECTED]] Sent: 18 September 2001 10:37 To: [EMAIL PROTECTED] Subject: Re: Inconsistent behaviour in Servlet output Hi, Billy, Did you check how many times the request is issued ? You can check this by including a System.out.println("....") in you servlet and look at the console to see how many times it is displayed for each "single" request. (I don't know about Adobe SVG add-in, but this was the source of a bug with the Adobe Acrobat plug-in). Pierre-Yves -----Message d'origine----- De : A mailing list for discussion about Sun Microsystem's Java Servlet API Technology. [mailto:[EMAIL PROTECTED]]De la part de Graham, Billy Envoy� : mardi 18 septembre 2001 09:36 � : [EMAIL PROTECTED] Objet : Inconsistent behaviour in Servlet output Hi to all. I have a problem that I've been trying to overcome for a number of days now and cannot see what is going wrong - hopefully someone will be able to point me in the right direction. I am still fairly new to servlets so please excuse me if the problem I pose is basic. I have written a servlet that queries a database, extracts the data and writes the data to the client (MSIE5.5) as SVG (XML) where it is displayed as graphs by the Adobe SVG add-in (V2). All this works perfectly - most of the time! Sometimes the graphs do not display in the correct position, totally messing up the display. To source the 'bug' I have written out various variables to a file on the server and examined them afterwards. Basically some of the variables I am using as counters, to place the graphs on-screen, occasionally change value 'for no reason at all' that I can determine, certainly I am not changing them directly in my code. I use doGet() to send my data request to the servlet from a web page. This usually works fine, but if I edit the URL data directly, in the client browser address line, to select different data then the resultant graphs are usually not displayed correctly (i.e. the file shows the counter variables have incremented incorrectly). If however I then click on 'REFRESH' on the client browser (with the manually edited URL still in force) the new graphs then display OK on the second time of asking. This behaviour seems to be consistent. The only clue to what is going on is that the web server displays two messages during the erroneous manual editing phase but only one message during the 'good' REFRESH phase. I have displayed the messages below in full but I have to admit I only have basic knowledge in this area so am not sure what they mean. Can anyone please point me in the right direction??? Manual Editing messages (2 off) : [1]: Tue, 18 Sep 2001 08:02:01 GMT+01 localhost/127.0.0.1 - 80: GET /servlet/QSee4?Dep=BG&Ana=PLUTO&Controls=VER1&Tests=Na&Tests=CL&Tests=Ca HTTP/1.1 200 OK 4080 [2]: Tue, 18 Sep 2001 08:02:02 GMT+01 localhost/127.0.0.1 - 80: GET /servlet/QSee4?Dep=BG&Ana=PLUTO&Controls=VER1&Tests=Na&Tests=CL&Tests=Ca HTTP/1.1 200 OK 68138 REFRESH message (1 off) : [1]: Tue, 18 Sep 2001 08:03:13 GMT+01 localhost/127.0.0.1 - 80: GET /servlet/QSee4?Dep=BG&Ana=PLUTO&Controls=VER1&Tests=Na&Tests=CL&Tests=Ca HTTP/1.1 200 OK 4080 Many thanks in anticipation. Regards, Billy Graham. ___________________________________________________________________________ To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff SERVLET-INTEREST". Archives: http://archives.java.sun.com/archives/servlet-interest.html Resources: http://java.sun.com/products/servlet/external-resources.html LISTSERV Help: http://www.lsoft.com/manuals/user/user.html ___________________________________________________________________________ To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff SERVLET-INTEREST". Archives: http://archives.java.sun.com/archives/servlet-interest.html Resources: http://java.sun.com/products/servlet/external-resources.html LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
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