Many servlet’s developers are confuse about the different between “ServletConfig” and “ServletContext”. Actually the “ServletContext” name is quite confusing, it should change to “AppConfig” or “AppContext” in the future release 🙂
ContextConfig
1) This is one per “web application”, access globally by all the servlets’ class
2) web.xml – within the web-app element and outside the servlet element
<web-app ...>
<servlet>
<servlet-name>ServletName</servlet-name>
<servlet-class>com.mkyong.ServletDemo</servlet-class>
</servlet>
<context-param>
<param-name>email</param-name>
<param-value>[email protected]</param-value>
</context-param>
</web-app>
3) Servlet code
getServletContext().getInitParameter("email")
==> See the ServletContext example here
ServletConfig
1) This is one per “servlet”, only access for each specific servlet
2) web.xml – within the servlet element
<web-app ...>
<servlet>
<servlet-name>ServletName</servlet-name>
<servlet-class>com.mkyong.ServletDemo</servlet-class>
<init-param>
<param-name>email</param-name>
<param-value>[email protected]</param-value>
</init-param>
</servlet>
</web-app>
3) Servlet code
getServletConfig().getInitParameter("email")
==> See the ServletContext example here
hi mkyong,
please put example of connecting mongoDb with servlet
with appConfig
Sir ur tutorial is very understable….
I am really amazed of ur explaination…..I am also one of ur fan….
Nice and i am a fan of your Java tutorial.
Noor Alam
(SCJP,SCWCD,SCBCD)
Hi Thanks , it is really amazing tutorial ,
but just one question what do u mean by
one per “web application” & This is one per “servlet” ?
I think so we can have multiple initial parameters per servlet and per web.xml
A web app can contains many servlets.
one per “web application”, means it can access by “any” of the servlets within the application, globally.
one per “servlet”, means it can only access for “a” specific servlet.
Is this clear?