Package org.eclipse.rdf4j.workbench.proxy

Class CacheFilter

java.lang.Object

org.eclipse.rdf4j.workbench.proxy.CacheFilter

All Implemented Interfaces:

javax.servlet.Filter

public class CacheFilter
extends Object
implements javax.servlet.Filter

Resource cache expiry filter for Tomcat 6, based on code authored by Saket Kumar.

Author:

Dale Visser

See Also:

• Enable Caching in Tomcat 6

Field Summary

Fields

Modifier and Type	Field	Description
static final long	MAX_EXPIRY	Maximum allowed expiry lifetime in seconds, set to one year according to the advice in RFC 2616.
static final long	MIN_EXPIRY	Minimum allowed expiry lifetime, zero, which corresponds to not caching at all.

Constructor Summary

Constructors

Constructor	Description
CacheFilter()

Method Summary

Modifier and Type	Method	Description
void	destroy()	Make stored references available for garbage collection.
void	doFilter(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res, javax.servlet.FilterChain chain)	Set a maximum expiry Cache-Control header applicable to the client and to intermediate caching servers.
void	init(javax.servlet.FilterConfig config)	Parse the Cache-Control configuration parameter as a long integer, and set the filter expiry value, modulo the minimum and maximum expiry constraints.

Methods inherited from class java.lang.Object

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

Field Details

MAX_EXPIRY

public static final long MAX_EXPIRY

Maximum allowed expiry lifetime in seconds, set to one year according to the advice in RFC 2616.

See Also:

• RFC 2616: HTTP/1.1
• Constant Field Values

MIN_EXPIRY

public static final long MIN_EXPIRY

Minimum allowed expiry lifetime, zero, which corresponds to not caching at all.

See Also:

• Constant Field Values

Constructor Details

CacheFilter

public CacheFilter()

Method Details

doFilter

public void doFilter(javax.servlet.ServletRequest req,
 javax.servlet.ServletResponse res,
 javax.servlet.FilterChain chain)
              throws IOException,
javax.servlet.ServletException

Set a maximum expiry Cache-Control header applicable to the client and to intermediate caching servers.

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

init

public void init(javax.servlet.FilterConfig config)
          throws javax.servlet.ServletException

Parse the Cache-Control configuration parameter as a long integer, and set the filter expiry value, modulo the minimum and maximum expiry constraints. If the configuration parameter is not present, or not a valid long integer value, then no Cache-Control headers will be applied by the filter.

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

See Also:

• MIN_EXPIRY
• MAX_EXPIRY

destroy

public void destroy()

Make stored references available for garbage collection.

Specified by:

destroy in interface javax.servlet.Filter