servletcontext and servletconfig

[anita dhar]

what is the difference between servletcontext and servletconfig
in which situations we are using these
any practical example
[ June 07, 2007: Message edited by: David O'Meara ]

[David O'Meara]

Please dont write all in capitals, as it is considered "shouting" and is not very nice.

thanks,
Dave

[Ben Souther]

They're different objects with different purposes.

The best place to go for answers to "difference between" questions like this is the the API.

You can find a link to the J2EE API in my signature.
[ June 07, 2007: Message edited by: Ben Souther ]

[Joe Harry]

You use ServletContext when you want information that should span across your entire web app. You use ServletConfig when you want information that should span your specific servlets. The HFSJ explains this clearly!

[Cameron Wallace McKenzie]

ServletConfig is specific to a given servlet mapping.

For example, you could have one TaxPortlet, but create 52 mappings, one for each state, in the web.xml file. For each state, you put a ServletConfig mapping for the state tax rate. As a result, each servlet mapping is unique - the TaxPortlet mapping for Nevada has a different state tax rate than the one for Florida.

On the other hand, ServletContext is common to all Servlets in a given war, so while each ServletMapping, for each state perhaps, would have a unique value for the state tax rate, EVERY Servlet in the war would share a common federal tax rate.

Hope that didn't make it more confusing.

-Cameron

[Ben Souther]

Originally posted by Cameron W. McKenzie:
ServletConfig is specific to a given servlet mapping.

For example, you could have one TaxPortlet, but create 52 mappings, one for each state, in the web.xml file. For each state, you put a ServletConfig mapping for the state tax rate. As a result, each servlet mapping is unique - the TaxPortlet mapping for Nevada has a different state tax rate than the one for Florida.

On the other hand, ServletContext is common to all Servlets in a given war, so while each ServletMapping, for each state perhaps, would have a unique value for the state tax rate, EVERY Servlet in the war would share a common federal tax rate.

Hope that didn't make it more confusing.

-Cameron

Correction:
The config object is specific to each servlet entry.
Init params don't go in the mapping entries.
They go in the servlet entries.

You can do what you've described by having multiple servlet entries, all using the same servlet class, each having it's own servlet meapping.