Package org.springframework.session.web.http

Class SessionRepositoryFilter<S extends Session>

java.lang.Object

org.springframework.session.web.http.SessionRepositoryFilter<S>

Type Parameters:

S - the Session type.

All Implemented Interfaces:

javax.servlet.Filter

@Order(-2147483598)
public class SessionRepositoryFilter<S extends Session>
extends Object

Switches the HttpSession implementation to be backed by a Session. The SessionRepositoryFilter wraps the HttpServletRequest and overrides the methods to get an HttpSession to be backed by a Session returned by the SessionRepository. The SessionRepositoryFilter uses a HttpSessionIdResolver (default CookieHttpSessionIdResolver) to bridge logic between an HttpSession and the Session abstraction. Specifically:

• The session id is looked up using HttpSessionIdResolver.resolveSessionIds(javax.servlet.http.HttpServletRequest) . The default is to look in a cookie named SESSION.
• The session id of newly created Session is sent to the client using HttpSessionIdResolver.setSessionId(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, String)
• The client is notified that the session id is no longer valid with HttpSessionIdResolver.expireSession(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

The SessionRepositoryFilter must be placed before any Filter that access the HttpSession or that might commit the response to ensure the session is overridden and persisted properly.

Since:

1.0

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ALREADY_FILTERED_SUFFIX	Suffix that gets appended to the filter name for the "already filtered" request attribute.
static final int	DEFAULT_ORDER	The default filter order.
static final String	INVALID_SESSION_ID_ATTR	Invalid session id (not backed by the session repository) request attribute name.
static final String	SESSION_REPOSITORY_ATTR	The session repository request attribute name.

Constructor Summary

Constructors

Constructor	Description
SessionRepositoryFilter(SessionRepository<S> sessionRepository)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
void	destroy()
final void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain filterChain)	This doFilter implementation stores a request attribute for "already filtered", proceeding without filtering again if the attribute is already there.
protected void	doFilterInternal(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, javax.servlet.FilterChain filterChain)	Same contract as for doFilter, but guaranteed to be just invoked once per request within a single request thread.
protected void	doFilterNestedErrorDispatch(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, javax.servlet.FilterChain filterChain)	Typically an ERROR dispatch happens after the REQUEST dispatch completes, and the filter chain starts anew.
protected String	getAlreadyFilteredAttributeName()	Return the name of the request attribute that identifies that a request is already filtered.
void	init(javax.servlet.FilterConfig config)
void	setHttpSessionIdResolver(HttpSessionIdResolver httpSessionIdResolver)	Sets the HttpSessionIdResolver to be used.

Methods inherited from class java.lang.Object

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

Field Details

SESSION_REPOSITORY_ATTR

public static final String SESSION_REPOSITORY_ATTR

The session repository request attribute name.

INVALID_SESSION_ID_ATTR

public static final String INVALID_SESSION_ID_ATTR

Invalid session id (not backed by the session repository) request attribute name.

DEFAULT_ORDER

public static final int DEFAULT_ORDER

The default filter order.

See Also:

• Constant Field Values

ALREADY_FILTERED_SUFFIX

public static final String ALREADY_FILTERED_SUFFIX

Suffix that gets appended to the filter name for the "already filtered" request attribute.

See Also:

• Constant Field Values

Constructor Details

SessionRepositoryFilter

public SessionRepositoryFilter(SessionRepository<S> sessionRepository)

Creates a new instance.

Parameters:

sessionRepository - the SessionRepository to use. Cannot be null.

Method Details

setHttpSessionIdResolver

public void setHttpSessionIdResolver(HttpSessionIdResolver httpSessionIdResolver)

Sets the HttpSessionIdResolver to be used. The default is a CookieHttpSessionIdResolver.

Parameters:

httpSessionIdResolver - the HttpSessionIdResolver to use. Cannot be null.

doFilterInternal

protected void doFilterInternal(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response,
 javax.servlet.FilterChain filterChain)
                         throws javax.servlet.ServletException,
IOException

Same contract as for doFilter, but guaranteed to be just invoked once per request within a single request thread.

Provides HttpServletRequest and HttpServletResponse arguments instead of the default ServletRequest and ServletResponse ones.

Parameters:

request - the request

response - the response

filterChain - the FilterChain

Throws:

javax.servlet.ServletException - thrown when a non-I/O exception has occurred

IOException - thrown when an I/O exception of some sort has occurred

See Also:

• Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)

doFilterNestedErrorDispatch

protected void doFilterNestedErrorDispatch(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response,
 javax.servlet.FilterChain filterChain)
                                    throws javax.servlet.ServletException,
IOException

Typically an ERROR dispatch happens after the REQUEST dispatch completes, and the filter chain starts anew. On some servers however the ERROR dispatch may be nested within the REQUEST dispatch, e.g. as a result of calling sendError on the response. In that case we are still in the filter chain, on the same thread, but the request and response have been switched to the original, unwrapped ones.

Sub-classes may use this method to filter such nested ERROR dispatches and re-apply wrapping on the request or response. ThreadLocal context, if any, should still be active as we are still nested within the filter chain.

Parameters:

request - the request

response - the response

filterChain - the filter chain

Throws:

javax.servlet.ServletException - if request is not HTTP request

IOException - in case of I/O operation exception

doFilter

public final void doFilter(javax.servlet.ServletRequest request,
 javax.servlet.ServletResponse response,
 javax.servlet.FilterChain filterChain)
                    throws javax.servlet.ServletException,
IOException

This doFilter implementation stores a request attribute for "already filtered", proceeding without filtering again if the attribute is already there.

Specified by:

doFilter in interface javax.servlet.Filter

Parameters:

request - the request

response - the response

filterChain - the filter chain

Throws:

javax.servlet.ServletException - if request is not HTTP request

IOException - in case of I/O operation exception

getAlreadyFilteredAttributeName

protected String getAlreadyFilteredAttributeName()

Return the name of the request attribute that identifies that a request is already filtered.

The default implementation takes the configured name of the concrete filter instance and appends ".FILTERED". If the filter is not fully initialized, it falls back to its class name.

Returns:

the name of request attribute indicating already filtered request

See Also:

• ALREADY_FILTERED_SUFFIX

init

public void init(javax.servlet.FilterConfig config)

Specified by:

init in interface javax.servlet.Filter

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Filter