Module org.eclipse.jetty.ee9.servlets

Package org.eclipse.jetty.ee9.servlets

Class PushCacheFilter

java.lang.Object

org.eclipse.jetty.ee9.servlets.PushCacheFilter

All Implemented Interfaces:

jakarta.servlet.Filter

@ManagedObject("Push cache based on the HTTP \'Referer\' header")
public class PushCacheFilter
extends Object
implements jakarta.servlet.Filter

A filter that builds a cache of secondary resources associated to primary resources.

A typical request for a primary resource such as index.html is immediately followed by a number of requests for secondary resources. Secondary resource requests will have a Referer HTTP header that points to index.html, which is used to associate the secondary resource to the primary resource.

Only secondary resources that are requested within a (small) time period from the request of the primary resource are associated with the primary resource.

This allows to build a cache of secondary resources associated with primary resources. When a request for a primary resource arrives, associated secondary resources are pushed to the client, unless the request carries If-xxx header that hint that the client has the resources in its cache.

If the init param useQueryInKey is set, then the query string is used as as part of the key to identify a resource

Constructor Summary

Constructors

Constructor	Description
PushCacheFilter()

Method Summary

Modifier and Type	Method	Description
void	clearPushCache()
void	destroy()
void	doFilter(jakarta.servlet.ServletRequest req, jakarta.servlet.ServletResponse resp, jakarta.servlet.FilterChain chain)
Map<String,String>	getPushCache()
void	init(jakarta.servlet.FilterConfig config)
void	renewPushCache()

Methods inherited from class java.lang.Object

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

Constructor Details

PushCacheFilter

public PushCacheFilter()

Method Details

init

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

Specified by:

init in interface jakarta.servlet.Filter

Throws:

jakarta.servlet.ServletException

doFilter

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

Specified by:

doFilter in interface jakarta.servlet.Filter

Throws:

IOException

jakarta.servlet.ServletException

destroy

public void destroy()

Specified by:

destroy in interface jakarta.servlet.Filter

getPushCache

@ManagedAttribute("The push cache contents")
public Map<String,String> getPushCache()

renewPushCache

@ManagedOperation(value="Renews the push cache contents",
                  impact="ACTION")
public void renewPushCache()

clearPushCache

@ManagedOperation(value="Clears the push cache contents",
                  impact="ACTION")
public void clearPushCache()