setting Context attributes in web.xml/server.xml?
Hi folks, I'm porting a servlet-based reporting system from iPlanet to TOmcat 4.1.12, and it initialises itself based on a context attribute 'baseDir'. iPlanet lets you set initial context attributes through the server. How do I set these in Tomcat4? Is it even possible? If iPlanet 4 has a feature tomcat doesn't, I'd be amazed. NB: I've tried context parameters, which tomcat does support, but they're no good. To clarify, I need an attribute I can retrieve via ServletContext con = getServletContext(); String dirname = (String) con.getAttribute(baseDir); to return the value. Being able to do this in web.xml would be extremely useful... (Worst case scenario, I can write a new servlet and init-on-startup it to explicitly set the attribute, but that's clankier than a bicycle made of saucepans) -- Rasputin :: Jack of All Trades - Master of Nuns -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: setting Context attributes in web.xml/server.xml?
Howdy, You can do this in your app's web.xml: context-param param-namebaseDir/param-name param-value/foo/bar/param-value /context-param And then in your servlet: String baseDir = getServletContext().getInitParameter(baseDir); If iPlanet 4 has a feature tomcat doesn't, I'd be amazed. If it were a spec-mandated feature, like context-params, then I'd be more than amazed: I'd be fairly angry ;) Yoav Shapira Millennium ChemInformatics -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
* Andy Eastham [EMAIL PROTECTED] [1140 16:40]: Rasputin, It's in web.xml Sorry, I can't see it. There's a context-param element, but I need a context *attribute*, and I don't think they can be set in tomcat. See sample chapter on www.moreservlets.com for more info. Actually, I bought the book :) -- Rasputin :: Jack of All Trades - Master of Nuns -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
On Wed, 27 Nov 2002, Rasputin wrote: Date: Wed, 27 Nov 2002 17:08:20 + From: Rasputin [EMAIL PROTECTED] Reply-To: Tomcat Users List [EMAIL PROTECTED], Rasputin [EMAIL PROTECTED] To: Andy Eastham [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: setting Context attributes in web.xml/server.xml? * Andy Eastham [EMAIL PROTECTED] [1140 16:40]: Rasputin, It's in web.xml Sorry, I can't see it. There's a context-param element, but I need a context *attribute*, and I don't think they can be set in tomcat. The context-param element, as you note, sets a context init parameter, not a context attribute. Context attributes must be set programatically, not from a web.xml file. A convenient way to set things up is to create a ServletContextListener (assumes you're running Tomcat 4 or later) and configure it in a listener element in web.xml. The contextInitialized() method will be called when your web application is first started, and that is a perfect place to set up whatever context attributes you need. See sample chapter on www.moreservlets.com for more info. Actually, I bought the book :) Craig -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
Please read the online documentation page: http://jakarta.apache.org/tomcat/tomcat-4.1-doc/config/context.html Under heading Context Parameters. Boris Rasputin wrote: * Andy Eastham [EMAIL PROTECTED] [1140 16:40]: Rasputin, It's in web.xml Sorry, I can't see it. There's a context-param element, but I need a context *attribute*, and I don't think they can be set in tomcat. See sample chapter on www.moreservlets.com for more info. Actually, I bought the book :) -- Rasputin :: Jack of All Trades - Master of Nuns -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- \\V// (o o) --ooO--(_)--Ooo- You know you've achieved perfection in design, NOT when you have nothing more to add, but when you have nothing more to remove. . Boris Prochazka E-mail: [EMAIL PROTECTED] Arenavagen 33, Box 101 http://www.ipunplugged.com SE-121 28 Stockholm Globen [home] +46 8 - 6040786 [office] +46 8 - 7255919 SWEDEN [mobile] +46 70 - 5125122 -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
* Boris Prochazka [EMAIL PROTECTED] [1159 17:59]: Please read the online documentation page: http://jakarta.apache.org/tomcat/tomcat-4.1-doc/config/context.html Under heading Context Parameters. Sorry, to clarify : element, but I need a context *attribute*, and I don't think they can be set in tomcat. context Parameter != context attribute. Thanks anyway! -- Rasputin :: Jack of All Trades - Master of Nuns -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
* Craig R. McClanahan [EMAIL PROTECTED] [1153 17:53]: On Wed, 27 Nov 2002, Rasputin wrote: * Andy Eastham [EMAIL PROTECTED] [1140 16:40]: Rasputin, It's in web.xml Sorry, I can't see it. There's a context-param element, but I need a context *attribute*, and I don't think they can be set in tomcat. The context-param element, as you note, sets a context init parameter, not a context attribute. Context attributes must be set programatically, not from a web.xml file. Gotcha - makes sense actually, as getInitParameter returns a String, whereas getAttribute returns an Object. A convenient way to set things up is to create a ServletContextListener (assumes you're running Tomcat 4 or later) and configure it in a listener element in web.xml. The contextInitialized() method will be called when your web application is first started, and that is a perfect place to set up whatever context attributes you need. Lovely, that's the sort of mechanism I was looking for - is it portable between servlet containers though? For the record, the load-on-startup hack works pretty well. Cheers. -- Rasputin :: Jack of All Trades - Master of Nuns -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: setting Context attributes in web.xml/server.xml?
Howdy, Lovely, that's the sort of mechanism I was looking for - is it portable between servlet containers though? For the record, the load-on-startup hack works pretty well. Cheers. Yes, it's portable. The ServletContextListener is part of the SRV 2.3 spec. Yoav Shapira Millennium ChemInformatics -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
On Wed, 27 Nov 2002, Rasputin wrote: Date: Wed, 27 Nov 2002 18:43:46 + From: Rasputin [EMAIL PROTECTED] Reply-To: Tomcat Users List [EMAIL PROTECTED], Rasputin [EMAIL PROTECTED] To: Tomcat Users List [EMAIL PROTECTED] Subject: Re: setting Context attributes in web.xml/server.xml? * Craig R. McClanahan [EMAIL PROTECTED] [1153 17:53]: On Wed, 27 Nov 2002, Rasputin wrote: * Andy Eastham [EMAIL PROTECTED] [1140 16:40]: Rasputin, It's in web.xml Sorry, I can't see it. There's a context-param element, but I need a context *attribute*, and I don't think they can be set in tomcat. The context-param element, as you note, sets a context init parameter, not a context attribute. Context attributes must be set programatically, not from a web.xml file. Gotcha - makes sense actually, as getInitParameter returns a String, whereas getAttribute returns an Object. A convenient way to set things up is to create a ServletContextListener (assumes you're running Tomcat 4 or later) and configure it in a listener element in web.xml. The contextInitialized() method will be called when your web application is first started, and that is a perfect place to set up whatever context attributes you need. Lovely, that's the sort of mechanism I was looking for - is it portable between servlet containers though? ServletContextListener is indeed portable to any Servlet 2.3 or later container. APIs that start java. or javax. are portable (although sometimes version specific), while APIs that start org.apache. are not portable. :-). For the record, the load-on-startup hack works pretty well. Cheers. Load-on-startup is indeed a hack (although it's about the only way to do this for pre-Servlet-2.3), because there is no guarantee that the servlet container will leave your servlet in memory for the lifetime of the web application. Craig -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
* Craig R. McClanahan [EMAIL PROTECTED] [1125 20:25]: Lovely, that's the sort of mechanism I was looking for - is it portable between servlet containers though? ServletContextListener is indeed portable to any Servlet 2.3 or later container. APIs that start java. or javax. are portable (although sometimes version specific), while APIs that start org.apache. are not portable. Right, thanks. It's more elegant, so is probably The Right Thing... For the record, the load-on-startup hack works pretty well. Cheers. Load-on-startup is indeed a hack (although it's about the only way to do this for pre-Servlet-2.3), because there is no guarantee that the servlet container will leave your servlet in memory for the lifetime of the web application. Damn, I was folowing all this up until you said that :) Unless I've got this back-asswards, once the Attribute is saved in the ServletContext ( which happens in init() ), won't it stay there? I thought that was the point of a ServletContext? Sure, it'll vanish when the server restarts, but if the WorkAround servlet init() method replaces it during 'load-on-startup', it shouldn't matter, should it? -- Rasputin :: Jack of All Trades - Master of Nuns -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: setting Context attributes in web.xml/server.xml?
On Thu, 28 Nov 2002, Rasputin wrote: Date: Thu, 28 Nov 2002 01:19:24 + From: Rasputin [EMAIL PROTECTED] To: Craig R. McClanahan [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: setting Context attributes in web.xml/server.xml? * Craig R. McClanahan [EMAIL PROTECTED] [1125 20:25]: Lovely, that's the sort of mechanism I was looking for - is it portable between servlet containers though? ServletContextListener is indeed portable to any Servlet 2.3 or later container. APIs that start java. or javax. are portable (although sometimes version specific), while APIs that start org.apache. are not portable. Right, thanks. It's more elegant, so is probably The Right Thing... For the record, the load-on-startup hack works pretty well. Cheers. Load-on-startup is indeed a hack (although it's about the only way to do this for pre-Servlet-2.3), because there is no guarantee that the servlet container will leave your servlet in memory for the lifetime of the web application. Damn, I was folowing all this up until you said that :) Unless I've got this back-asswards, once the Attribute is saved in the ServletContext ( which happens in init() ), won't it stay there? I thought that was the point of a ServletContext? Sure, it'll vanish when the server restarts, but if the WorkAround servlet init() method replaces it during 'load-on-startup', it shouldn't matter, should it? It will stay in the ServletContext attributes until you remove it, or until the web application is shut down. Most people who set things up in the init() method of a load-on-startup servlet will also clean up after themselves in the destroy() method of the same servlet -- for example, if you open a database connection at startup, you generally want to close it at shutdown. With a load-on-startup servlet, there are no guarantees how many times this might happen during the lifetime of your application. With contextInitialized() and contextDestroyed() methods of ServletContextListener, you get that guarantee. That's why the latter is better. Craig -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
