I got it .The confusion came when I was comparing the same with filter chain mapping in web.xml.
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Somple conclusion I came on :
For Servlets , in web.xml, there is no kind a rule for order of <servlet-mapping>, container will recurse through the requesr URI , from left right , finding the longest posible match.
If found stop further search and calls the servlet , of it will cut down left part seperated by / and search the rest recursively.
The same will continue till it finds a match , If it doesnt , it will directed to default servlet, if default servlet doesnt exisis , an error will be shown .
In case of filter, mapping is done with every filter URL , but in the order declared in web.xml to create a chain of filters and calls them accordingly.
Please correct me if I have mistated some where.