Re: placing the properties file in tomcat

[Kamesh Challa <kamesh@netexpress.net>]

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
> > >>
> > >> __________________________________________________
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> > >
> > 
> > 
> > 
> > -- 
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> 
> 
> =====
> Poorav Chaudhari
> 
> __________________________________________________
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