Chris, Thanks for the feedback.. very much appreciated!
>-----Original Message----- >From: Christopher Schultz [mailto:ch...@christopherschultz.net] >Subject: Re: Logging request parameters - Filter vs Servlet > >So you need to log the "txtAPN" parameter, right? Yes. Actually, the contents of the listbox... as you'll see below. >> Those are the parameters I'm trying to capture, along with the map image url. >> A. We'd like to know how many requests actually generated a map image. > >Can you tell that, just from a parameter value? I would think that the >URL itself would more likely tell you if a map was generated. No, I couldn't tell that from a parameter value, which is why I knew I had to log from within the webapp somewhere, but I didn't know whether logging should happen in a filter or at a specific place in the model. Or should I log in the "fascade" (pattern)? I wanted the logs to capture the url so that I knew the model reached a point where it generated an image. http://planning.maricopa.gov/agsoutput/_ags_mapdee1a8d3a28f49a48f44aaf4dc4cc316.jpg Those images are only there for 20 min, so that url is already dead. >> B. We'd like to know whether this app is searching for parcels >> primarily in the unincorporated areas of the County, or parcels >> located within a city jurisdiction. That part I can figure out once >> I know which parcels people are searching. > >Simply logging the parcels used in searches would allow you to do that, >as you've said. The RequestDumperValve logs a /ton/ of information, and >probably wouldn't get you what you want. > >I'm not sure where you read it, but that sounds like a platitude applied >as a blanket admonition not to log in your webapp. If it's appropriate >for your situation, then feel free to do it. > >Back to the original "filter" question: logging using a filter is >perfectly acceptable if it's the right solution (see below for questions >that might lead you to other options). Writing the filter is trivial: >just implement the javax.servlet.Filter interface and be sure to read >the javadoc for it before you try: you'll thank yourself, later. > >You can even use ServletContext.log() to write to the context log if you >want. Otherwise, feel free to use your webapp's log4j or other logging >facility (you'll have to configure this yourself). Just don't use >System.out :) > >One might argue that blindly logging request parameters is not >particularly useful. For instance, a quick look at your interface >indicates that you can add several plots of land before performing the >search. Those initial "add" operations may be of little use to you. You are right. >Instead, you may wish to log them only at a certain point in your >workflow. Since most requests go to "oppositioncase.faces", you may not >be able to map your Filter to a URL pattern that is fine-grained enough. >Instead, it might make more sense to log this data when you know there's >a reason to log it. Since you're expecting to perform statistical >analysis on the data, you might even consider writing it directly to a >database instead of to a plain-old log file. I'm going this route for now: FacesContext.getCurrentInstance().getExternalContext().log(the string buffer of the parcel listbox); FacesContext.getCurrentInstance().getExternalContext().log(the map URL); Produces: Mar 30, 2011 12:02:35 PM org.apache.catalina.core.ApplicationContext log INFO: PARCEL = '125-27-089' Mar 30, 2011 12:02:45 PM org.apache.catalina.core.ApplicationContext log INFO: http://planning.maricopa.gov/agsoutput/_ags_map08eb57df58224e1884e17a3e8a59b555.jpg Mar 30, 2011 12:03:16 PM org.apache.catalina.core.ApplicationContext log INFO: PARCEL = '125-27-089' OR PARCEL = '125-27-090' OR PARCEL = '125-27-091' Mar 30, 2011 12:03:27 PM org.apache.catalina.core.ApplicationContext log INFO: http://planning.maricopa.gov/agsoutput/_ags_map1a6e940afbd1494794c8d22b36f3a11a.jpg >Cool webapp, by the way! Thanks! > >NB: The "ctrl" key isn't always the modifier key to use to de-select >items from a multi-select list. I think that's a Microsoft Windows >convention, but it's CMD-click on Mac and probably something like >META-click on *NIX. Sadly, my department wanted that blurb on there. They forget stuff. Leo
