com.hazelcast.web
Class WebFilter

java.lang.Object
  com.hazelcast.web.WebFilter

All Implemented Interfaces:

javax.servlet.Filter

Direct Known Subclasses:

SpringAwareWebFilter

public class WebFilter
extends Object
implements javax.servlet.Filter

Provides clustered sessions by backing session data with an IMap.

Using this filter requires also registering a SessionListener to provide session timeout notifications. Failure to register the listener when using this filter will result in session state getting out of sync between the servlet container and Hazelcast.

This filter supports the following <init-param> values:

• use-client: When enabled, a HazelcastClient is used to connect to the cluster, rather than joining as a full node. (Default: false)
• config-location: Specifies the location of an XML configuration file that can be used to initialize the HazelcastInstance (Default: None; the HazelcastInstance is initialized using its own defaults)
• client-config-location: Specifies the location of an XML configuration file that can be used to initialize the HazelcastInstance. This setting is only checked when use-client is set to true. (Default: Falls back on config-location)
• instance-name: Names the HazelcastInstance. This can be used to reference an already- initialized HazelcastInstance in the same JVM (Default: The configured instance name, or a generated name if the configuration does not specify a value)
• shutdown-on-destroy: When enabled, shuts down the HazelcastInstance when the filter is destroyed (Default: true)
• map-name: Names the IMap the filter should use to persist session details (Default: "_web_" + ServletContext.getServletContextName(); e.g. "_web_MyApp")
• session-ttl-seconds: Sets the time-to-live for the IMap used to persist session details (Default: Uses the existing MapConfig setting for the IMap, which defaults to infinite)
• sticky-session: When enabled, optimizes IMap interactions by assuming individual sessions are only used from a single node (Default: true)
• deferred-write: When enabled, optimizes IMap interactions by only writing session attributes at the end of a request. This can yield significant performance improvements for session-heavy applications (Default: false)
• cookie-name: Sets the name for the Hazelcast session cookie (Default: "hazelcast.sessionId"
• cookie-domain: Sets the domain for the Hazelcast session cookie (Default: null)
• cookie-secure: When enabled, indicates the Hazelcast session cookie should only be sent over secure protocols (Default: false)
• cookie-http-only: When enabled, marks the Hazelcast session cookie as "HttpOnly", indicating it should not be available to scripts (Default: false)
  • cookie-http-only requires a Servlet 3.0-compatible container, such as Tomcat 7+ or Jetty 8+

Nested Class Summary

protected class	WebFilter.HazelcastHttpSession
protected static class	WebFilter.LocalCacheEntry
protected class	WebFilter.RequestWrapper
protected static class	WebFilter.ResponseWrapper

Field Summary

protected javax.servlet.FilterConfig	filterConfig
protected static String	HAZELCAST_REQUEST
protected static String	HAZELCAST_SESSION_ATTRIBUTE_SEPARATOR
protected static String	HAZELCAST_SESSION_COOKIE_NAME
protected static ILogger	LOGGER
protected static WebFilter.LocalCacheEntry	NULL_ENTRY
protected javax.servlet.ServletContext	servletContext
static String	WEB_FILTER_ATTRIBUTE_KEY

Constructor Summary

WebFilter()

WebFilter(Properties properties)

Method Summary

protected WebFilter.HazelcastHttpSession	createHazelcastHttpSession(String id, javax.servlet.http.HttpSession originalSession, boolean deferredWrite) HazelcastHttpSession instance creation is split off to a separate method to allow subclasses to return a customized / extended version of HazelcastHttpSession.
protected WebFilter.HazelcastHttpSession	createNewSession(WebFilter.RequestWrapper requestWrapper, String existingSessionId)
void	destroy()
protected void	destroySession(WebFilter.HazelcastHttpSession session, boolean invalidate) Destroys a session, determining if it should be destroyed clusterwide automatically or via expiry.
void	doFilter(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res, javax.servlet.FilterChain chain)
protected HazelcastInstance	getInstance(Properties properties)
void	init(javax.servlet.FilterConfig config)
protected void	shutdownInstance()

Methods inherited from class java.lang.Object

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

Field Detail

WEB_FILTER_ATTRIBUTE_KEY

public static final String WEB_FILTER_ATTRIBUTE_KEY

HAZELCAST_SESSION_ATTRIBUTE_SEPARATOR

protected static final String HAZELCAST_SESSION_ATTRIBUTE_SEPARATOR

See Also:

Constant Field Values

LOGGER

protected static final ILogger LOGGER

NULL_ENTRY

protected static final WebFilter.LocalCacheEntry NULL_ENTRY

HAZELCAST_REQUEST

protected static final String HAZELCAST_REQUEST

See Also:

Constant Field Values

HAZELCAST_SESSION_COOKIE_NAME

protected static final String HAZELCAST_SESSION_COOKIE_NAME

See Also:

Constant Field Values

servletContext

protected javax.servlet.ServletContext servletContext

filterConfig

protected javax.servlet.FilterConfig filterConfig

Constructor Detail

WebFilter

public WebFilter()

WebFilter

public WebFilter(Properties properties)

Method Detail

init

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

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

createNewSession

protected WebFilter.HazelcastHttpSession createNewSession(WebFilter.RequestWrapper requestWrapper,
                                                          String existingSessionId)

createHazelcastHttpSession

protected WebFilter.HazelcastHttpSession createHazelcastHttpSession(String id,
                                                                    javax.servlet.http.HttpSession originalSession,
                                                                    boolean deferredWrite)

HazelcastHttpSession instance creation is split off to a separate method to allow subclasses to return a customized / extended version of HazelcastHttpSession.

Parameters:

id - the session id

originalSession - the original session

deferredWrite - whether writes are deferred

Returns:

a new HazelcastHttpSession instance

destroySession

protected void destroySession(WebFilter.HazelcastHttpSession session,
                              boolean invalidate)

Destroys a session, determining if it should be destroyed clusterwide automatically or via expiry.

Parameters:

session - the session to be destroyed locally

invalidate - true if the session has been invalidated and should be destroyed on all nodes in the cluster; otherwise, false to only remove the session globally if this node was the final node referencing it

doFilter

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

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

destroy

public final void destroy()

Specified by:

destroy in interface javax.servlet.Filter

getInstance

protected HazelcastInstance getInstance(Properties properties)
                                 throws javax.servlet.ServletException

Throws:

javax.servlet.ServletException

shutdownInstance

protected void shutdownInstance()