Package org.apache.catalina.filters

Class RequestFilter

java.lang.Object

org.apache.catalina.filters.FilterBase

org.apache.catalina.filters.RequestFilter

All Implemented Interfaces:

Filter

Direct Known Subclasses:

RemoteAddrFilter, RemoteHostFilter

public abstract class RequestFilter
extends FilterBase

Implementation of a Filter that performs filtering based on comparing the appropriate request property (selected based on which subclass you choose to configure into your Container's pipeline) against the regular expressions configured for this Filter.

This filter is configured by setting the allow and/or deny properties to a regular expressions (in the syntax supported by Pattern) to which the appropriate request property will be compared. Evaluation proceeds as follows:

• The subclass extracts the request property to be filtered, and calls the common process() method.
• If there is a deny expression configured, the property will be compared to the expression. If a match is found, this request will be rejected with a "Forbidden" HTTP response.
• If there is a allow expression configured, the property will be compared to the expression. If a match is found, this request will be allowed to pass through to the next filter in the current pipeline.
• If a deny expression was specified but no allow expression, allow this request to pass through (because none of the deny expressions matched it).
• The request will be rejected with a "Forbidden" HTTP response.

Field Summary

Fields

Modifier and Type	Field	Description
protected Pattern	allow	The regular expression used to test for allowed requests.
protected Pattern	deny	The regular expression used to test for denied requests.
protected int	denyStatus	The HTTP response status code that is used when rejecting denied request.

Fields inherited from class org.apache.catalina.filters.FilterBase

sm

Constructor Summary

Constructors

Constructor	Description
RequestFilter()

Method Summary

Modifier and Type	Method	Description
abstract void	doFilter(ServletRequest request, ServletResponse response, FilterChain chain)	Extract the desired request property, and pass it (along with the specified request and response objects) to the protected process() method to perform the actual filtering.
String	getAllow()
String	getDeny()
int	getDenyStatus()
protected boolean	isConfigProblemFatal()	Determines if an exception when calling a setter or an unknown configuration attribute triggers the failure of the this filter which in turn will prevent the web application from starting.
protected void	process(String property, ServletRequest request, ServletResponse response, FilterChain chain)	Perform the filtering that has been configured for this Filter, matching against the specified request property.
void	setAllow(String allow)	Set the regular expression used to test for allowed requests for this Filter, if any.
void	setDeny(String deny)	Set the regular expression used to test for denied requests for this Filter, if any.
void	setDenyStatus(int denyStatus)	Set response status code that is used to reject denied request.

Methods inherited from class org.apache.catalina.filters.FilterBase

getLogger, init

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface jakarta.servlet.Filter

destroy

Field Details

allow

protected Pattern allow

The regular expression used to test for allowed requests.

deny

protected Pattern deny

The regular expression used to test for denied requests.

denyStatus

protected int denyStatus

The HTTP response status code that is used when rejecting denied request. It is 403 by default, but may be changed to be 404.

Constructor Details

RequestFilter

public RequestFilter()

Method Details

getAllow

public String getAllow()

Returns:

the regular expression used to test for allowed requests for this Filter, if any; otherwise, return null.

setAllow

public void setAllow(String allow)

Set the regular expression used to test for allowed requests for this Filter, if any.

Parameters:

allow - The new allow expression

getDeny

public String getDeny()

Returns:

the regular expression used to test for denied requests for this Filter, if any; otherwise, return null.

setDeny

public void setDeny(String deny)

Set the regular expression used to test for denied requests for this Filter, if any.

Parameters:

deny - The new deny expression

getDenyStatus

public int getDenyStatus()

Returns:

response status code that is used to reject denied request.

setDenyStatus

public void setDenyStatus(int denyStatus)

Set response status code that is used to reject denied request.

Parameters:

denyStatus - The status code for deny

doFilter

public abstract void doFilter(ServletRequest request,
 ServletResponse response,
 FilterChain chain)
                       throws IOException,
ServletException

Extract the desired request property, and pass it (along with the specified request and response objects) to the protected process() method to perform the actual filtering. This method must be implemented by a concrete subclass.

Parameters:

request - The servlet request to be processed

response - The servlet response to be created

chain - The filter chain

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet error occurs

isConfigProblemFatal

protected boolean isConfigProblemFatal()

Description copied from class: FilterBase

Determines if an exception when calling a setter or an unknown configuration attribute triggers the failure of the this filter which in turn will prevent the web application from starting.

Overrides:

isConfigProblemFatal in class FilterBase

Returns:

true if a problem should trigger the failure of this filter, else false

process

protected void process(String property,
 ServletRequest request,
 ServletResponse response,
 FilterChain chain)
                throws IOException,
ServletException

Perform the filtering that has been configured for this Filter, matching against the specified request property.

Parameters:

property - The request property on which to filter

request - The servlet request to be processed

response - The servlet response to be processed

chain - The filter chain

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet error occurs