CODEWITHSUNDEEP
javajspservletsservlet-filters
MDP
MDP

Reputation: 4267

how Filters handle Session

some of you advise me to handle sessions using filters. I studied a little about the filter following some guides found on the internet, and wrote a filter referring this guide.

I saw that the filter is called for every component of my page (css, images etc); is there a way to call it just when a jsp or a servlet is load? I need a method that can understand if jsp or a servlet is load, in order to make some stuff inside my filter.

Upvotes: 2

Views: 145

Answers (2)

Jops
Jops

Reputation: 22705

First off, please don't be misled by the purpose of the tutorial in the link you have specified. Session handling is always done through cookies, URL-rewriting (or for the more advanced, SSL). He's merely using filters to enhance application security, by ensuring the user is redirected to the login page, whenever he goes directly to an "avoid-url".

Think about a filter, a physical filter. Whether it be an excel filter or a physical gravel filter. It stands between one thing and another thing:

enter image description here

Java web filters can do the same thing:

enter image description here

Just like you can choose which water bottle to filter, you can decide which requests you want to filter. You do that using the filter-mapping element in web.xml. You can specify individual servlet names, or a url pattern.

Upvotes: 0

Kojotak
Kojotak

Reputation: 2070

Yes, you can do that. Just change the url-pattern for your session filter.

If you are using some web framework (spring mvc,...) with one dispatching servlet, you can map your filter only to this servlet using servlet-name and requests to other resources (js, css) will not be intercepted by this filter.

Upvotes: 1

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