NullPointerExceptions.....getServletContext(GenericServlet.java:209)

[FreshmenProgrammer]

Hello,

First I would like to say thanks in advance for the help!!

This is the error im getting.
SEVERE: null
java.lang.NullPointerException
at javax.servlet.GenericServlet.getServletContext(GenericServlet.java:209)

I'm not sure if im not setting the application scope variable right or im not getting it right because i'm always getting a null value. Please let me know what you think. Thank you!

EISDAO eis = new EISDAO();
eis.setDBHost(config.getInitParameter("dbhost"));
//etc etc.. 

// i set the application scope variable in an init like this
config.getServletContext().setAttribute("eisdao", eis);

//
public SISDAO getEISDAO() {

return (EISDAO)getServletContext().getAttribute("eisdao");
	}

 

[sedj]

If you need to set session attributes ...

In a JSP, use

session.getAttribute("name");

and

session.setAttribute("name", "value");

In a servlet, you should use :

HttpSession session = request.getSession();
...
session.getAttribute("name");
...
session.setAttribute("name", "value");

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http://www.primrose.org.uk

 

[FreshmenProgrammer]

I need to set an Application Scope variable in a Abstract controller. So the whole app will have access to the EIS object.

 

[sedj]

Oops, sorry - missed the application level bit.

Unless someone knows of a better way, I would do it like this :

Create a servlet which handles initialization of application parameters.
Create a class which holds the variables you wish (or has a Hahsmap or table into which you can insert/retrieve arbitrary parameters). Make the member variable static, and create static accessor methods.

when the "Initialization" servlet fires up (ie override the servlets init() method), read your parameters, and use the class I mentioned before to set your parameters.

Then all your application code has to do is call the static methods on that class to retrieve various variables.

--------------------------------------------------
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http://www.primrose.org.uk