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servlet context syntax

Posted on 2006-11-08
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Last Modified: 2013-11-24
i have this .....

TreeNode rootNode = (TreeNode)getServletContext().getAttribute("mediaLibRootTreeNode"); which resides in a back end section

now i have to recreate this in the front end section

now normally i have this ..
getServlet().getServletContext().getAttribute("rolms_front_dir").toString() to get to the front bit.
but now how do i set my rootNode of TreeNode type to get the servlet attribute?
i'm not sure if i'm explaining this properly but i'm hoping you guys will understand this when u see it.
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Question by:blue-genie
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by:blue-genie
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ok let me try explain it this way. i have a getContext.setAttribute("") that gets set on startup of tomcat.
i have 2 folders, the admin and front bits, and in the front, i have a jsp that needs to get hold of that attribute.
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objects earned 500 total points
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use something like:

Object value = application.getAttribute(name);
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by:blue-genie
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objects, it returns a null, but the value is set when the server starts up - it's in the logs.
i'm thinking it doesn't know where the servletcontext is. so i have to set somethign to the rolms_front_dir bit, but then get another attribute.

i want to do something like this

Object value = pageContext.getServletConfig().getServletContext().getAttribute("rolms_front_dir").toString();
            out.println(value); //this prints out correctly
            TreeNode rootNode=(TreeNode)value.getAttribute("mediaLibRootTreeNode");

the other bit gives me a cannot resolve symbol

symbol  : method getAttribute (java.lang.String)
location: class java.lang.Object
            TreeNode rootNode=(TreeNode)value.getAttribute("mediaLibRootTreeNode");
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by:objects
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where exactly is that code?

>    TreeNode rootNode=(TreeNode)value.getAttribute("mediaLibRootTreeNode");

'value' is a string, it doesn't have a getAttribute method

do u mean:

TreeNode rootNode=(TreeNode) pageContext.getServletConfig().getServletContext().getAttribute("mediaLibRootTreeNode");
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by:blue-genie
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that code is in the jsp in the front bit

thing is the servlet is in the back, and the attribute gets set there, and i'm trying to access it from the front.
The web application has a administration section and a front view.
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by:blue-genie
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ok, part 2, we've managed to pull something back but...when we getClass().getName() returns TreeNode
but if we cast to TreeNode - throws a classcast exeptinon?
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by:objects
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can u post your code
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by:blue-genie
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thanks objects.... appreciate it

my serlet on start up calls

treeNodeCreator.buildCourseListWithLearningProgramesAsTree(getServletContext());

the buildCourse... method does a whole bunch of things then at the end

servletContext.setAttribute("mediaLibRootTreeNode", rootNode);

in my jsp....

we've been fiddling around with this a bit, so might look a bit disjointed...

TreeNode rootNode = null;

try{
      TreeNode rootNode =getServletContext().getContext("/" + getServletContext().getAttribute("rolms_admin_dir")).getAttribute("mediaLibRootTreeNode");
} catch (ClassCastException ce) {
      out.println(ce.getMessage());
}
out.println("Object type: " + rootNode.getClass().toString());//returns TreeNode

i need what's returned by the servet attribute to be cast to the TreeNode so that i can access it's methods....

shout if this is still not enough.

            
            
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by:objects
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there is no casting in that code??
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by:blue-genie
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yeah sorry
when we try TreeNode rootNode = (TreeNode)getServletContext().getContext("/" + getServletContext().getAttribute("rolms_admin_dir")).getAttribute("mediaLibRootTreeNode");

it throws the error.
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by:objects
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> out.println("Object type: " + rootNode.getClass().toString());//returns TreeNode

that doesn't make sense, if u were getting a CCE then rootNode would be null and that line would not return TreNode
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by:blue-genie
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ok, like is said, we've been playing around with the code and putting out prints and trying all sorts of wierd stuff.

bottom line, when we return the attribute from the servlet attribute and do a getClass on it, it brings back TreeNode, however when we explicitly cast it to TreeNode it throws the exception.
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by:objects
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if thats the case then they must be different TreeNode classes.
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by:blue-genie
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is that possible if they're both the same package and all?
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by:blue-genie
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managed to come right, thanks for your efforts anyway.
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