[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: placing the properties file in tomcat

To: Poorav Chaudhari <pooravc@yahoo.com>
Subject: Re: placing the properties file in tomcat
From: Kamesh Challa <kamesh@netexpress.net>
Date: Wed, 2 Apr 2003 17:50:43 -0500
Cc: ajug-members@ajug.org
In-Reply-To: <20030402170937.57614.qmail@web14911.mail.yahoo.com>
References: <20030402170937.57614.qmail@web14911.mail.yahoo.com>
User-Agent: Internet Messaging Program (IMP) 3.1

Poorav, 
The init-param was basically for the Struts framework but not part of the 
servlet parameters. 
 So, basically you're looking for an alternative to access the global property 
file across the board. Correct?? 

Well, there are many methods to configure the global properties. Let's discuss 
some of the them for better understanding. 
1. You could configure them within the property xml files of the servers 
(weblogic or tomcat or what ever your server may be) and get the values from 
the context. (I would not suggest this method) 
2. Create an interface class and store the values within the interface as final 
variables and hence available where ever you want. (I would not suggest this 
method too. Not scalable at all) 
3. One of the better methods I'd suggest: 
   - Create the external property object as you've created already. 
   - Create a class which makes use of the ResourceBundle to load the 
properties in the constructor of the object
   - Have static methods to get the property values from the resource bundle.
   - Use this class where ever you want. 

This should be simple enough. 

If you want to know more about ResourceBundle class
http://java.sun.com/docs/books/tutorial/i18n/resbundle/concept.html
and how to use with property file at:
http://java.sun.com/docs/books/tutorial/i18n/resbundle/propfile.html


Hope this is of some help...

Thanks and BR, 
--Kamesh Challa
Yash Technologies Inc.


Quoting Poorav Chaudhari <pooravc@yahoo.com>:

> Kamesh,
> 
> Thanks for shedding some light, but now i have a few more questions. Please
> bear with me. you can possibly show me the first few steps of how i should
> approach my problem. I am already using the application.resources file for
> my
> displaying errors, although i must admit it's inner working i have yet to
> fully
> understand. anywho, now i would like to make the use of another properties
> file
> that stores things like paths to certain files, server name etc. These
> obviously i need at various points in the application. let this property
> file
> be app.properties. from what i understood,  i can place this file in the
> /WEB-INF/classes folder and i my entry for it in the web.xml will be
> something
> like
> 
>   <servlet>
>     <servlet-name>action</servlet-name>
>     <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
> 
>     <init-param>
>       <param-name>application</param-name>
>       <param-value>app.properties</param-value>
>     </init-param>
> 
>     <load-on-startup>1</load-on-startup>
>   </servlet>
> 
> I don't know what to substitute servlet-name and servlet-class with. and
> again,
> how do i access these properties from my beans and jsps. 
> 
> I did look at the java.util.ResourceBundle, but that didn'tdo much except
> for
> give me a conceptual understanding of the usage of resourcebundle. 
> 
> i think an explanation on this will greatly clear my doubts, and i will be
> very
> grateful,
> 
> Thank you
> 
> 
> --- Kamesh Challa <kamesh@netexpress.net> wrote:
> > 
> > Poorav,
> >     If I understand it correctly you want to understand where/how you'd use
> 
> > properties file within your STRUTS based application. 
> > 
> > If so.. read ahead... 
> > 
> > One of the frequent uses of property files within STRUTS FRAMEWORK is to 
> > customize/standardize error messages across the application. 
> > 
> > Let's take an example of defining system wide error messages for clarity.
> > 
> > You'd have to do 4 basic things to accomplish this:
> > 
> > 1. Define error messages in a property file as key value pairs (The usual
> > way;-
> > )). 
> > 
> > Eg: Say you've ApplicationResources.properties file that had the error
> > messages 
> > defined 
> > 
> > error.last_name.required=<li><b>Last name</b> is required</li>
> > 
> > Note: Generally HTML tags are included along with the error messages to be
> 
> > prominent. 
> > 
> > 2. Use the error messages to populate the
> > org.apache.struts.action.ActionErrors 
> > object in case of validation fails in your Application Action Form via the
> 
> > validate method.  
> > 
> > Eg: You may do something like this in your application Action Form in the
> 
> > validate method (per say)
> > 
> >   if (last_name is equal to null || some other condition) {
> > 	errors.add("last_name", 
> >                new ActionError("error.last_name.required"));
> >   }
> > 
> > 3. Define the property file to be available for the framework as the
> servlet 
> > init parameter within web.xml file:
> >  
> > Eg: The way you would define the property file is to mention within the
> > action 
> > servlet tag. 
> > 
> > <servlet>
> >       <servlet-name>action</servlet-name>
> >      
> <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
> >       <init-param>
> >          <param-name>application</param-name>
> >          <param-value>org.XXX.YYY.ZZZ.ApplicationResources</param-value>
> >       </init-param>
> > 
> > 
> > 4. Of course you'd be using the <html:errors/> tag in your front end jsps
> to 
> > pull the error messages out of the errors object. 
> > 
> > This is a simple overview of HOW property file is used. There are tons of
> 
> > varieties of usage. 
> > 
> > While using property files just remember "load 'em once on startup and
> use
> > 'em 
> > over and over". 
> > 
> > Check out java.util.ResourceBundle. 
> > 
> > 
> > HTH....
> > 
> > Thanks and BR, 
> > --Kamesh Challa
> > Yash Technologies Inc.
> > 
> > 
> > Quoting Poorav Chaudhari <pooravc@yahoo.com>:
> > 
> > > I have a feeling i am missing the jist of how to use properties. I read
> the
> > > short tutorial on using properties to manage program attributes. but in
> > that
> > > it
> > > is explained with the use of a standalone application. The use and
> > > implementation of properties in a servlet environment seems to be a
> > > completely
> > > different ball game. my application is specifically in struts
> framework.
> > > now
> > > the properties that i define in the properties file, will be used
> through
> > > out
> > > the application. can i find some sort of discussion on this online?
> > > something
> > > that will help me clarify this confusion? Thanks.
> > > 
> > > Poorav
> > > 
> > > 
> > > --- Calvin Yu <cyu77@yahoo.com> wrote:
> > > > 
> > > > Here's how you load it up as a Properties object:
> > > > 
> > > > 1.
> ServletContext.getResourceAsStream("/WEB-INF/classes/foo.properties");
> > > > 
> > > > 2. Object.getClass().getClassLoader("foo.properties");
> > > > 
> > > > Calvin
> > > > 
> > > > 
> > > > On Tue,  1 Apr 2003 12:28:34 -0500, Kamesh Challa
> <kamesh@netexpress.net>
> > > 
> > > > wrote:
> > > > 
> > > > > Couple of methods. 1. Use ResourceBundle rBundle = 
> > > > > ResourceBundle.getBundle("<your property file name>");
> > > > > rBundle.getString("<Your property name>");
> > > > >
> > > > > 2. Use:
> > > > > init parameters within your web.xml and use it. (Struts
> applications
> > are
> > > 
> > > > > classic examples)
> > > > >
> > > > > I remember some examples within the samples given under tomcat.
> Check
> > it
> > > 
> > > > > out.
> > > > >
> > > > > HTH...
> > > > >
> > > > > Thanks, --Kamesh Challa
> > > > > Yash Technologies Inc.
> > > > >
> > > > >
> > > > > Quoting Poorav Chaudhari <pooravc@yahoo.com>:
> > > > >
> > > > >> For my web application, i have created a properties file. It is
> placed
> > > 
> > > > >> in
> > > > >> the
> > > > >> WEB-INF/classes folder. to test the properties file i also created a
> 
> > > > >> small
> > > > >> command line program. that worked fine, i was able to print the
> values
> > > 
> > > > >> of
> > > > >> properties. but when i run the web app on tomcat, i get an error
> > > saying
> > > > >> that
> > > > >> the properties file cannot be found. what am i missing.
> > > > >>
> > > > >> Thank you in advance.
> > > > >>
> > > > >>
> > > > >> =====
> > > > >> Poorav Chaudhari
> > > > >>
> > > > >> __________________________________________________
> > > > >> Do you Yahoo!?
> > > > >> Yahoo! Tax Center - File online, calculators, forms, and more
> > > > >> http://platinum.yahoo.com
> > > > >>
> > > > >
> > > > 
> > > > 
> > > > 
> > > > -- 
> > > > Using M2, Opera's revolutionary e-mail client:
> http://www.opera.com/m2/
> > > > 
> > > 
> > > 
> > > =====
> > > Poorav Chaudhari
> > > 
> > > __________________________________________________
> > > Do you Yahoo!?
> > > Yahoo! Tax Center - File online, calculators, forms, and more
> > > http://platinum.yahoo.com
> > > 
> 
> 
> =====
> Poorav Chaudhari
> 
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Tax Center - File online, calculators, forms, and more
> http://tax.yahoo.com
>

Follow-Ups:
- Re: placing the properties file in tomcat
  - From: Poorav Chaudhari <pooravc@yahoo.com>

References:
- Re: placing the properties file in tomcat
  - From: Poorav Chaudhari <pooravc@yahoo.com>

Prev by Date: Re: Interfaces, abstract classes. Why?
Next by Date: Re: Interfaces, abstract classes. Why?
Prev by thread: Re: placing the properties file in tomcat
Next by thread: Re: placing the properties file in tomcat
Index(es):
- Date
- Thread