Re: solved-Re: config.getInitParameter() still returning null
On Fri, 9 Mar 2001, Markus Keller [OrcaSoft] wrote: > Hello Milt > > > > The value of init parameter var1 is: > > > <%= > > > getServletConfig().getInitParameter("var1") > > > %> > > > > > I use this: > > <%= getServletContext().getInitParameter("ApplicationName") %> > > instead of getServletConfig() and it works. Well, they're not really interchangable, they're meant for different purposes. Basically, according to the 2.2 spec, there are context parameters, and servlet parameters. A context is basically a web application, so context parameters are intended to be use for application-wide parameters. Servlet parameters are only for a specific servlet (i.e. a subset of the application). Sure, you can avoid using servlet parameters, and only use context parameters, but whether that's the most appropriate and/or cleanest way to do things depends on what you're doing. Milt Epstein Research Programmer Software/Systems Development Group Computing and Communications Services Office (CCSO) University of Illinois at Urbana-Champaign (UIUC) [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
Re: solved-Re: config.getInitParameter() still returning null
Hello Milt > > The value of init parameter var1 is: > > <%= > > getServletConfig().getInitParameter("var1") > > %> > > I use this: <%= getServletContext().getInitParameter("ApplicationName") %> instead of getServletConfig() and it works. Markus - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
Re: solved-Re: config.getInitParameter() still returning null
On Thu, 8 Mar 2001, Milt Epstein wrote: [ ... ] > > > Testy > > > <%@ page > import="java.util.*" > %> > <%! > Enumeration names; > String name; > %> > > The value of init parameter var1 is: > <%= > getServletConfig().getInitParameter("var1") > %> > > > The init parameters are: > > <% > names = getServletConfig().getInitParameterNames(); > while (names.hasMoreElements()) { >name = (String) names.nextElement(); > %> > > <%= >name > %> > = > <%= >getServletConfig().getInitParameter(name) > %> > <% > } > %> > > > > BTW, it still works if I substitute "config" for "getServletConfig()" everywhere above. Milt Epstein Research Programmer Software/Systems Development Group Computing and Communications Services Office (CCSO) University of Illinois at Urbana-Champaign (UIUC) [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
Re: solved-Re: config.getInitParameter() still returning null
On Thu, 8 Mar 2001 [EMAIL PROTECTED] wrote: > OK this is how to get init-params working for JSP > > Include this in your web.xml file > > > > >foo > > >bar > > > > > And then in your JSP page: > > String s = application.getInitParameter("foo"); [ ... ] I'm sorry, but I must object :-). This isn't how to get init-param's working with JSP, so it's not a solution -- and I wouldn't even call it a workaround, because you don't need to do a workaround. What I said in a previous note should work. I constructed an example to demonstrate it. Here's the relevant stuff from the web.xml file (which is located in /webapps/blah/WEB-INF/): testy testy.jsp var1 value1 var2 value2 testy /testy.jsp I've appended the JSP after my sig. I used a URL of the form: http://my.domain.com/blah/testy.jsp The only thing I had trouble with was where the test.jsp file should go. I tried it in /webapps/blah/WEB-INF/classes/, and it didn't work. I put it in /webapps/blah/, and it did work. I'm not sure I fully understand why that is, but at least I did get the init-param's working. Milt Epstein Research Programmer Software/Systems Development Group Computing and Communications Services Office (CCSO) University of Illinois at Urbana-Champaign (UIUC) [EMAIL PROTECTED] Testy <%@ page import="java.util.*" %> <%! Enumeration names; String name; %> The value of init parameter var1 is: <%= getServletConfig().getInitParameter("var1") %> The init parameters are: <% names = getServletConfig().getInitParameterNames(); while (names.hasMoreElements()) { name = (String) names.nextElement(); %> <%= name %> = <%= getServletConfig().getInitParameter(name) %> <% } %> - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
solved-Re: config.getInitParameter() still returning null
OK this is how to get init-params working for JSP Include this in your web.xml file foo bar And then in your JSP page: String s = application.getInitParameter("foo"); Milt Epstein <[EMAIL PROTECTED]> 03/08/01 08:00 AM Please respond to tomcat-user To: [EMAIL PROTECTED] cc: Subject: Re: config.getInitParameter() still returning null On Thu, 8 Mar 2001, Bo Xu wrote: > [EMAIL PROTECTED] wrote: > > > The config.getInitParameter() called from within a JSP page is > > returning null. After changing the web.xml file numerous times and > > trying all the suggestions from java.sun.com and the tomcat archives I > > still cannot resolve this problem. > > Does anyone know why we can't access the init parameters? > > thanks in advance > > > > Here is what my web.xml file looks like (does not work): > > > > > > > > > > Error > > > > > > org.apache.jasper.runtime.JspServlet > > > > > > debug > > true > > > > > > > > > > and my JSP code: > > <% > > String s = config.getInitParameter("debug"); > > if (s == null) { > > out.println("Init param must be null!"); > > } > > else{ > > out.println("Init param is "+s); > > } > > %> > > Hi :-) I didn't ever use jsp to get init parameters, but I guess > the reasons is: in your WEB_INF/web.xml, you only define > a servlet definition with some init parameters, but you didn't > define a servlet-mapping; and/so I guess you invoked your > servlet without url-pattern(servlet-mapping name) -> I guess > you use: http://localhost:8080/myapp/servlet/Myservlet , > so if you use Servlet, the following will return null: > - config.getInitParameter(...) > - this.getInitParameter(...) [ ... ] I could be wrong, but I don't believe you have to define servlet-mapping's to get init-param's to work, just having defined the servlet is sufficient. However, in the URL, you do need to use the specific servlet-name you used in the servlet definition. (That's because you can define the same servlet class multiple times, with different servlet-name's and different init-param's.) So, according to the above web.xml, the URL that should be used is: http://your.domain.com/yourwebappname/servlet/Error (No, I haven't tested this.) However, I just noticed that the original poster said that this is all happening in a JSP ("JSP page" is redundant :-) -- that throws a monkey wrench into the situation, and I'm not sure how it changes things. For example, I don't know how to set up init-param's in a JSP. Also, upon re-reading the above servlet definition, I'm not sure that's the right way to set up a JSP -- i.e. putting org.apache.jasper.runtime.JspServlet as the servlet-class (I assume that's the tomcat/jasper servlet that handles JSP's). I think you want to name your JSP .jsp, and just tell tomcat somewhere that it's a JSP. But again, I'm not sure how you'd set up init-param's for it (maybe you do have to fallback on the suggestion to use context init-param's, instead of servlet init-param's). Well, I think I may have just raised more confusion, but perhaps this will lead to some helpful discussion/ideas, and/or someone will post clearing things up. ... Hold on. I decided to do a google newsgroup search on this, to see if I can get more definite information, and looks like I found the answers. Check out the following posts: http://groups.google.com/groups?q=init-param+jsp&hl=en&lr=&safe=off&rnum=1&seld=964886773&ic=1 http://groups.google.com/groups?hl=en&lr=&safe=off&th=9eb4e0cd3b0f1fb6&rnum=9&seld=958627636&ic=1 Actually, I don't know if these URLs will work outside the context of my search -- if not, go to the google advanced newsgroups search page at: http://groups.google.com/advanced_group_search and enter "init-param jsp" in the "with all of the words" box (without the quotes) and "hanna" in the "Author" box (again, without the quotes). Basically, it looks like a servlet definition can specify *either* servlet-class or a jsp-file (those are the actual names of the tags used in web.xml). Note the warnings about what form of URL to use when you set things up this way, though. Milt Epstein Research Programmer Software/Systems Development Group Computing and Communications Services Office (CCSO) University of Illinois at Urbana-Champaign (UIUC) [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]