Package org.apache.catalina.valves

Class FilterValve

java.lang.Object

org.apache.catalina.util.LifecycleBase

org.apache.catalina.util.LifecycleMBeanBase

org.apache.catalina.valves.ValveBase

org.apache.catalina.valves.FilterValve

All Implemented Interfaces:

FilterConfig, MBeanRegistration, Contained, JmxEnabled, Lifecycle, Valve

public class FilterValve
extends ValveBase
implements FilterConfig

A Valve to wrap a Filter, allowing a user to run Servlet Filters as a part of the Valve chain.

There are some caveats you must be aware of when using this Valve to wrap a Filter:

• You get a separate instance of your Filter class distinct from any that may be instantiated within your application.
• Calls to FilterConfig.getFilterName() will return null.
• Calling FilterConfig.getServletContext() will return the proper ServletContext for a Valve/Filter attached to a <Context>, but will return a ServletContext which is nearly useless for any Valve/Filter specified on an <Engine> or >Host<.
• Your Filter MUST NOT wrap the ServletRequest or ServletResponse objects, or an exception will be thrown.

See Also:

• Valve
• Filter

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle

Lifecycle.SingleUse

Field Summary

Fields inherited from class org.apache.catalina.valves.ValveBase

asyncSupported, container, containerLog, next, sm

Fields inherited from interface org.apache.catalina.Lifecycle

AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

Constructors

Constructor	Description
FilterValve()

Method Summary

Modifier and Type	Method	Description
void	addInitParam(String paramName, String paramValue)	Adds an initialization parameter for the Filter.
String	getFilterClassName()	Gets the name of the class for the Filter.
String	getFilterName()	Get the name of the filter.
String	getInitParameter(String name)	Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.
Enumeration<String>	getInitParameterNames()	Returns the names of the filter's initialization parameters as an Enumeration of String objects, or an empty Enumeration if the filter has no initialization parameters.
ServletContext	getServletContext()	Returns a reference to the ServletContext in which the caller is executing.
void	invoke(Request request, Response response)	Perform request processing as required by this Valve.
void	setFilterClass(String filterClassName)	Sets the name of the class for the Filter.
void	setFilterClassName(String filterClassName)	Sets the name of the class for the Filter.
protected void	startInternal()	Start this component and implement the requirements of LifecycleBase.startInternal().
protected void	stopInternal()	Stop this component and implement the requirements of LifecycleBase.stopInternal().

Methods inherited from class org.apache.catalina.valves.ValveBase

backgroundProcess, getContainer, getDomainInternal, getNext, getObjectNameKeyProperties, initInternal, isAsyncSupported, setAsyncSupported, setContainer, setNext, toString

Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase

destroyInternal, getDomain, getObjectName, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister, unregister

Methods inherited from class org.apache.catalina.util.LifecycleBase

addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, getThrowOnFailure, init, removeLifecycleListener, setState, setState, setThrowOnFailure, start, stop

Methods inherited from class java.lang.Object

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

Constructor Details

FilterValve

public FilterValve()

Method Details

setFilterClass

public void setFilterClass(String filterClassName)

Sets the name of the class for the Filter.

Parameters:

filterClassName - The class name for the Filter.

setFilterClassName

public void setFilterClassName(String filterClassName)

Sets the name of the class for the Filter.

Parameters:

filterClassName - The class name for the Filter.

getFilterClassName

public String getFilterClassName()

Gets the name of the class for the Filter.

Returns:

The class name for the Filter.

addInitParam

public void addInitParam(String paramName,
 String paramValue)

Adds an initialization parameter for the Filter.

Parameters:

paramName - The name of the parameter.

paramValue - The value of the parameter.

getFilterName

public String getFilterName()

Description copied from interface: jakarta.servlet.FilterConfig

Get the name of the filter.

Specified by:

getFilterName in interface FilterConfig

Returns:

null

getServletContext

public ServletContext getServletContext()

Description copied from interface: jakarta.servlet.FilterConfig

Returns a reference to the ServletContext in which the caller is executing.

Specified by:

getServletContext in interface FilterConfig

Returns:

the ServletContext. Note that this will be of limited use if the Valve/Filter is not attached to a <Context>.

See Also:

• ServletContext

getInitParameter

public String getInitParameter(String name)

Description copied from interface: jakarta.servlet.FilterConfig

Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.

Specified by:

getInitParameter in interface FilterConfig

Parameters:

name - String specifying the name of the initialization parameter

Returns:

String containing the value of the initialization parameter

getInitParameterNames

public Enumeration<String> getInitParameterNames()

Description copied from interface: jakarta.servlet.FilterConfig

Returns the names of the filter's initialization parameters as an Enumeration of String objects, or an empty Enumeration if the filter has no initialization parameters.

Specified by:

getInitParameterNames in interface FilterConfig

Returns:

Enumeration of String objects containing the names of the filter's initialization parameters

startInternal

protected void startInternal()
                      throws LifecycleException

Description copied from class: ValveBase

Start this component and implement the requirements of LifecycleBase.startInternal().

Overrides:

startInternal in class ValveBase

Throws:

LifecycleException - if this component detects a fatal error that prevents this component from being used

stopInternal

protected void stopInternal()
                     throws LifecycleException

Description copied from class: ValveBase

Stop this component and implement the requirements of LifecycleBase.stopInternal().

Overrides:

stopInternal in class ValveBase

Throws:

LifecycleException - if this component detects a fatal error that prevents this component from being used

invoke

public void invoke(Request request,
 Response response)
            throws IOException,
ServletException

Description copied from interface: Valve

Perform request processing as required by this Valve.

An individual Valve MAY perform the following actions, in the specified order:

• Examine and/or modify the properties of the specified Request and Response.
• Examine the properties of the specified Request, completely generate the corresponding Response, and return control to the caller.
• Examine the properties of the specified Request and Response, wrap either or both of these objects to supplement their functionality, and pass them on.
• If the corresponding Response was not generated (and control was not returned, call the next Valve in the pipeline (if there is one) by executing getNext().invoke().
• Examine, but not modify, the properties of the resulting Response (which was created by a subsequently invoked Valve or Container).

A Valve MUST NOT do any of the following things:

• Change request properties that have already been used to direct the flow of processing control for this request (for instance, trying to change the virtual host to which a Request should be sent from a pipeline attached to a Host or Context in the standard implementation).
• Create a completed Response AND pass this Request and Response on to the next Valve in the pipeline.
• Consume bytes from the input stream associated with the Request, unless it is completely generating the response, or wrapping the request before passing it on.
• Modify the HTTP headers included with the Response after the getNext().invoke() method has returned.
• Perform any actions on the output stream associated with the specified Response after the getNext().invoke() method has returned.

Specified by:

invoke in interface Valve

Parameters:

request - The servlet request to be processed

response - The servlet response to be created

Throws:

IOException - if an input/output error occurs, or is thrown by a subsequently invoked Valve, Filter, or Servlet

ServletException - if a servlet error occurs, or is thrown by a subsequently invoked Valve, Filter, or Servlet