5) JSP application implicit object

In JSP, application is an implicit object of type ServletContext.

The instance of ServletContext is created only once by the web container when application or project is deployed on the server.

This object can be used to get initialization parameter from configuaration file (web.xml). It can also be used to get, set or remove attribute from the application scope.

This initialization parameter can be used by all jsp pages.

Example of application implicit object:

index.html

<form action="welcome">
<input type="text" name="uname">
<input type="submit" value="go"><br/>
</form>

web.xml file


<web-app>

<servlet>
<servlet-name>sonoojaiswal</servlet-name>
<jsp-file>/welcome.jsp</jsp-file>
</servlet>

<servlet-mapping>
<servlet-name>sonoojaiswal</servlet-name>
<url-pattern>/welcome</url-pattern>
</servlet-mapping>

<context-param>
<param-name>dname</param-name>
<param-value>sun.jdbc.odbc.JdbcOdbcDriver</param-value>
</context-param>

</web-app>

welcome.jsp

<% 

out.print("Welcome "+request.getParameter("uname"));

String driver=application.getInitParameter("dname");
out.print("driver name is="+driver);

%>

JSP Tutorial

5) JSP application implicit object

Example of application implicit object:

Output

Other topics in JSP implicit Objects