/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.messaging.simp.user;
import java.security.Principal;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
import org.springframework.messaging.simp.SimpMessageType;
import org.springframework.util.Assert;
import org.springframework.util.PathMatcher;
import org.springframework.util.StringUtils;
/**
* A default implementation of {@code UserDestinationResolver} that relies
* on a {@link SimpUserRegistry} to find active sessions for a user.
*
* <p>When a user attempts to subscribe, e.g. to "/user/queue/position-updates",
* the "/user" prefix is removed and a unique suffix added based on the session
* id, e.g. "/queue/position-updates-useri9oqdfzo" to ensure different users can
* subscribe to the same logical destination without colliding.
*
* <p>When sending to a user, e.g. "/user/{username}/queue/position-updates", the
* "/user/{username}" prefix is removed and a suffix based on active session id's
* is added, e.g. "/queue/position-updates-useri9oqdfzo".
*
* @author Rossen Stoyanchev
* @author Brian Clozel
* @since 4.0
*/
public class DefaultUserDestinationResolver implements UserDestinationResolver {
private static final Log logger = LogFactory.getLog(DefaultUserDestinationResolver.class);
private final SimpUserRegistry userRegistry;
private String prefix = "/user/";
private boolean keepLeadingSlash = true;
/**
* Create an instance that will access user session id information through
* the provided registry.
* @param userRegistry the registry, never {@code null}
*/
public DefaultUserDestinationResolver(SimpUserRegistry userRegistry) {
Assert.notNull(userRegistry, "'userRegistry' must not be null");
this.userRegistry = userRegistry;
}
/**
* Return the configured {@link SimpUserRegistry}.
*/
public SimpUserRegistry getSimpUserRegistry() {
return this.userRegistry;
}
/**
* The prefix used to identify user destinations. Any destinations that do not
* start with the given prefix are not be resolved.
* <p>The default prefix is "/user/".
* @param prefix the prefix to use
*/
public void setUserDestinationPrefix(String prefix) {
Assert.hasText(prefix, "prefix must not be empty");
this.prefix = prefix.endsWith("/") ? prefix : prefix + "/";
}
/**
* Return the configured prefix for user destinations.
*/
public String getDestinationPrefix() {
return this.prefix;
}
/**
* Provide the {@code PathMatcher} in use for working with destinations
* which in turn helps to determine whether the leading slash should be
* kept in actual destinations after removing the
* {@link #setUserDestinationPrefix userDestinationPrefix}.
* <p>By default actual destinations have a leading slash, e.g.
* {@code /queue/position-updates} which makes sense with brokers that
* support destinations with slash as separator. When a {@code PathMatcher}
* is provided that supports an alternative separator, then resulting
* destinations won't have a leading slash, e.g. {@code
* jms.queue.position-updates}.
* @param pathMatcher the PathMatcher used to work with destinations
* @since 4.3
*/
public void setPathMatcher(PathMatcher pathMatcher) {
if (pathMatcher != null) {
this.keepLeadingSlash = pathMatcher.combine("1", "2").equals("1/2");
}
}
@Override
public UserDestinationResult resolveDestination(Message<?> message) {
String sourceDestination = SimpMessageHeaderAccessor.getDestination(message.getHeaders());
ParseResult parseResult = parse(message);
if (parseResult == null) {
return null;
}
String user = parseResult.getUser();
Set<String> targetSet = new HashSet<>();
for (String sessionId : parseResult.getSessionIds()) {
String actualDestination = parseResult.getActualDestination();
String targetDestination = getTargetDestination(sourceDestination, actualDestination, sessionId, user);
if (targetDestination != null) {
targetSet.add(targetDestination);
}
}
String subscribeDestination = parseResult.getSubscribeDestination();
return new UserDestinationResult(sourceDestination, targetSet, subscribeDestination, user);
}
private ParseResult parse(Message<?> message) {
MessageHeaders headers = message.getHeaders();
String destination = SimpMessageHeaderAccessor.getDestination(headers);
if (destination == null || !checkDestination(destination, this.prefix)) {
return null;
}
SimpMessageType messageType = SimpMessageHeaderAccessor.getMessageType(headers);
Principal principal = SimpMessageHeaderAccessor.getUser(headers);
String sessionId = SimpMessageHeaderAccessor.getSessionId(headers);
if (SimpMessageType.SUBSCRIBE.equals(messageType) || SimpMessageType.UNSUBSCRIBE.equals(messageType)) {
if (sessionId == null) {
logger.error("No session id. Ignoring " + message);
return null;
}
int prefixEnd = this.prefix.length() - 1;
String actualDestination = destination.substring(prefixEnd);
if (!this.keepLeadingSlash) {
actualDestination = actualDestination.substring(1);
}
String user = (principal != null ? principal.getName() : null);
return new ParseResult(actualDestination, destination, Collections.singleton(sessionId), user);
}
else if (SimpMessageType.MESSAGE.equals(messageType)) {
int prefixEnd = this.prefix.length();
int userEnd = destination.indexOf('/', prefixEnd);
Assert.isTrue(userEnd > 0, "Expected destination pattern \"/user/{userId}/**\"");
String actualDestination = destination.substring(userEnd);
String subscribeDestination = this.prefix.substring(0, prefixEnd - 1) + actualDestination;
String userName = destination.substring(prefixEnd, userEnd);
userName = StringUtils.replace(userName, "%2F", "/");
Set<String> sessionIds;
if (userName.equals(sessionId)) {
userName = null;
sessionIds = Collections.singleton(sessionId);
}
else {
SimpUser user = this.userRegistry.getUser(userName);
if (user != null) {
if (user.getSession(sessionId) != null) {
sessionIds = Collections.singleton(sessionId);
}
else {
Set<SimpSession> sessions = user.getSessions();
sessionIds = new HashSet<>(sessions.size());
for (SimpSession session : sessions) {
sessionIds.add(session.getId());
}
}
}
else {
sessionIds = Collections.emptySet();
}
}
if (!this.keepLeadingSlash) {
actualDestination = actualDestination.substring(1);
}
return new ParseResult(actualDestination, subscribeDestination, sessionIds, userName);
}
else {
return null;
}
}
protected boolean checkDestination(String destination, String requiredPrefix) {
return destination.startsWith(requiredPrefix);
}
/**
* This method determines how to translate the source "user" destination to an
* actual target destination for the given active user session.
* @param sourceDestination the source destination from the input message.
* @param actualDestination a subset of the destination without any user prefix.
* @param sessionId the id of an active user session, never {@code null}.
* @param user the target user, possibly {@code null}, e.g if not authenticated.
* @return a target destination, or {@code null} if none
*/
@SuppressWarnings("unused")
protected String getTargetDestination(String sourceDestination, String actualDestination,
String sessionId, String user) {
return actualDestination + "-user" + sessionId;
}
@Override
public String toString() {
return "DefaultUserDestinationResolver[prefix=" + this.prefix + "]";
}
/**
* A temporary placeholder for a parsed source "user" destination.
*/
private static class ParseResult {
private final String actualDestination;
private final String subscribeDestination;
private final Set<String> sessionIds;
private final String user;
public ParseResult(String actualDest, String subscribeDest, Set<String> sessionIds, String user) {
this.actualDestination = actualDest;
this.subscribeDestination = subscribeDest;
this.sessionIds = sessionIds;
this.user = user;
}
public String getActualDestination() {
return this.actualDestination;
}
public String getSubscribeDestination() {
return this.subscribeDestination;
}
public Set<String> getSessionIds() {
return this.sessionIds;
}
public String getUser() {
return this.user;
}
}
}