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; 020 021/** 022 * A registry of currently connected users. 023 * 024 * @author Rossen Stoyanchev 025 * @since 4.2 026 */ 027public interface SimpUserRegistry { 028 029 /** 030 * Get the user for the given name. 031 * @param userName the name of the user to look up 032 * @return the user, or {@code null} if not connected 033 */ 034 SimpUser getUser(String userName); 035 036 /** 037 * Return a snapshot of all connected users. 038 * <p>The returned set is a copy and will not reflect further changes. 039 * @return the connected users, or an empty set if none 040 */ 041 Set<SimpUser> getUsers(); 042 043 /** 044 * Return the count of all connected users. 045 * @return the number of connected users 046 * @since 4.3.5 047 */ 048 int getUserCount(); 049 050 /** 051 * Find subscriptions with the given matcher. 052 * @param matcher the matcher to use 053 * @return a set of matching subscriptions, or an empty set if none 054 */ 055 Set<SimpSubscription> findSubscriptions(SimpSubscriptionMatcher matcher); 056 057}