001/* 002 * Copyright 2002-2016 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.messaging.simp.user; 018 019import java.util.Set; 020 021import org.springframework.lang.Nullable; 022 023/** 024 * A registry of currently connected users. 025 * 026 * @author Rossen Stoyanchev 027 * @since 4.2 028 */ 029public interface SimpUserRegistry { 030 031 /** 032 * Get the user for the given name. 033 * @param userName the name of the user to look up 034 * @return the user, or {@code null} if not connected 035 */ 036 @Nullable 037 SimpUser getUser(String userName); 038 039 /** 040 * Return a snapshot of all connected users. 041 * <p>The returned set is a copy and will not reflect further changes. 042 * @return the connected users, or an empty set if none 043 */ 044 Set<SimpUser> getUsers(); 045 046 /** 047 * Return the count of all connected users. 048 * @return the number of connected users 049 * @since 4.3.5 050 */ 051 int getUserCount(); 052 053 /** 054 * Find subscriptions with the given matcher. 055 * @param matcher the matcher to use 056 * @return a set of matching subscriptions, or an empty set if none 057 */ 058 Set<SimpSubscription> findSubscriptions(SimpSubscriptionMatcher matcher); 059 060}