Knowledge about filters and related knowledge about Filters

Knowledge about filters and related knowledge about Filters

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[Filter: Overview of filters]

• What is Filter:

Filters requests sent from the client to the server.

• Filter usage:

* Filter IP addresses, use dirty words, log on automatically, and compress responses...

• Use filter:

* Compile a class to implement the Filter interface:

* Configuration filter:

[Lifecycle of a filter]: (understanding)

• Filter creation and destruction:

* Creation: when the server is started.

* Destruction: when the server is shut down.

 

[FilterChain: Filter chain]

 

The filter execution sequence in the filter chain is related to the configuration sequence of <filter-mapping>.

 

* DoFilter (request, response); -- allow, allow to the next filter. If there is no next filter, it reaches the target resource.

 

[Filter-related configuration]

 

• <Url-pattern> Configuration:

 

* Full path match: Start With/demo4/demo1.jsp

 

* Directory match: Start with/and end with *./*/demo1 /*

 

* Extension matching: *. *. do *. action cannot start /.

 

 

 

• <Servlet-name> Configuration: intercept the Servlet according to the Servlet name.

 

 

 

• <Dispatcher> Configuration:

 

* REQUEST: default value.

 

* FORWARD: FORWARD.

 

* INCLUDE: contains.

 

* ERROR: ERROR page Jump. (Global ERROR page)