org.springframework.messaging.simp.user

Class DefaultUserDestinationResolver

java.lang.Object

org.springframework.messaging.simp.user.DefaultUserDestinationResolver

All Implemented Interfaces:

UserDestinationResolver

public class DefaultUserDestinationResolver
extends Object
implements UserDestinationResolver

A default implementation of UserDestinationResolver that relies on the UserSessionRegistry provided to the constructor to find the sessionIds associated with a user and then uses the sessionId to make the target destination unique.

When a user attempts to subscribe to "/user/queue/position-updates", the "/user" prefix is removed and a unique suffix added, resulting in something like "/queue/position-updates-useri9oqdfzo" where the suffix is based on the user's session and ensures it does not collide with any other users attempting to subscribe to "/user/queue/position-updates".

When a message is sent to a user with a destination such as "/user/{username}/queue/position-updates", the "/user/{username}" prefix is removed and the suffix added, resulting in something like "/queue/position-updates-useri9oqdfzo".

Since:

4.0

Author:

Rossen Stoyanchev, Brian Clozel

Constructor Summary

Constructors

Constructor and Description
DefaultUserDestinationResolver(UserSessionRegistry userSessionRegistry) Create an instance that will access user session id information through the provided registry.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkDestination(String destination, String requiredPrefix)
String	getDestinationPrefix() Return the prefix used to identify user destinations.
protected String	getTargetDestination(String sourceDestination, String sourceDestinationWithoutPrefix, String sessionId, String user) This methods determines the translated destination to use based on the source destination, the source destination with the user prefix removed, a session id, and the user for the session (if known).
UserSessionRegistry	getUserSessionRegistry() Return the configured UserSessionRegistry.
UserDestinationResult	resolveDestination(Message<?> message) Resolve the destination of the message to a set of actual target destinations.
void	setUserDestinationPrefix(String prefix) The prefix used to identify user destinations.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultUserDestinationResolver

public DefaultUserDestinationResolver(UserSessionRegistry userSessionRegistry)

Create an instance that will access user session id information through the provided registry.

Parameters:

userSessionRegistry - the registry, never null

Method Detail

setUserDestinationPrefix

public void setUserDestinationPrefix(String prefix)

The prefix used to identify user destinations. Any destinations that do not start with the given prefix are not be resolved.

The default value is "/user/".

Parameters:

prefix - the prefix to use

getDestinationPrefix

public String getDestinationPrefix()

Return the prefix used to identify user destinations. Any destinations that do not start with the given prefix are not be resolved.

By default "/user/queue/".

getUserSessionRegistry

public UserSessionRegistry getUserSessionRegistry()

Return the configured UserSessionRegistry.

resolveDestination

public UserDestinationResult resolveDestination(Message<?> message)

Description copied from interface: UserDestinationResolver

Resolve the destination of the message to a set of actual target destinations.

If the message is SUBSCRIBE/UNSUBSCRIBE, the returned set will contain a single translated target destination.

If the message represents data being sent to a user, the returned set may contain multiple target destinations, one for each active user session.

Specified by:

resolveDestination in interface UserDestinationResolver

Parameters:

message - the message with a user destination to be resolved

Returns:

the result of the resolution, or null if the resolution fails (e.g. not a user destination, or no user info available, etc)

checkDestination

protected boolean checkDestination(String destination,
                                   String requiredPrefix)

getTargetDestination

protected String getTargetDestination(String sourceDestination,
                                      String sourceDestinationWithoutPrefix,
                                      String sessionId,
                                      String user)

This methods determines the translated destination to use based on the source destination, the source destination with the user prefix removed, a session id, and the user for the session (if known).

Parameters:

sourceDestination - the source destination of the input message

sourceDestinationWithoutPrefix - the source destination without the user prefix

sessionId - the id of the session for the target message

user - the user associated with the session, or null

Returns:

a target destination, or null if none

toString

public String toString()

Overrides:

toString in class Object