/*
* Copyright 2002-2017 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.web.reactive.socket.server.support;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import reactor.core.publisher.Mono;
import org.springframework.context.Lifecycle;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
import org.springframework.web.reactive.socket.server.WebSocketService;
import org.springframework.web.server.MethodNotAllowedException;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.ServerWebInputException;
/**
* {@code WebSocketService} implementation that handles a WebSocket HTTP
* handshake request by delegating to a {@link RequestUpgradeStrategy} which
* is either auto-detected (no-arg constructor) from the classpath but can
* also be explicitly configured.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public class HandshakeWebSocketService implements WebSocketService, Lifecycle {
private static final String SEC_WEBSOCKET_KEY = "Sec-WebSocket-Key";
private static final String SEC_WEBSOCKET_PROTOCOL = "Sec-WebSocket-Protocol";
private static final boolean tomcatPresent = ClassUtils.isPresent(
"org.apache.tomcat.websocket.server.WsHttpUpgradeHandler",
HandshakeWebSocketService.class.getClassLoader());
private static final boolean jettyPresent = ClassUtils.isPresent(
"org.eclipse.jetty.websocket.server.WebSocketServerFactory",
HandshakeWebSocketService.class.getClassLoader());
private static final boolean reactorNettyPresent = ClassUtils.isPresent(
"reactor.ipc.netty.http.server.HttpServerResponse",
HandshakeWebSocketService.class.getClassLoader());
private static final boolean undertowPresent = ClassUtils.isPresent(
"io.undertow.websockets.WebSocketProtocolHandshakeHandler",
HandshakeWebSocketService.class.getClassLoader());
protected static final Log logger = LogFactory.getLog(HandshakeWebSocketService.class);
private final RequestUpgradeStrategy upgradeStrategy;
private volatile boolean running = false;
/**
* Default constructor automatic, classpath detection based discovery of the
* {@link RequestUpgradeStrategy} to use.
*/
public HandshakeWebSocketService() {
this(initUpgradeStrategy());
}
/**
* Alternative constructor with the {@link RequestUpgradeStrategy} to use.
* @param upgradeStrategy the strategy to use
*/
public HandshakeWebSocketService(RequestUpgradeStrategy upgradeStrategy) {
Assert.notNull(upgradeStrategy, "'upgradeStrategy' is required");
this.upgradeStrategy = upgradeStrategy;
}
private static RequestUpgradeStrategy initUpgradeStrategy() {
String className;
if (tomcatPresent) {
className = "TomcatRequestUpgradeStrategy";
}
else if (jettyPresent) {
className = "JettyRequestUpgradeStrategy";
}
else if (reactorNettyPresent) {
className = "ReactorNettyRequestUpgradeStrategy";
}
else if (undertowPresent) {
className = "UndertowRequestUpgradeStrategy";
}
else {
throw new IllegalStateException("No suitable default RequestUpgradeStrategy found");
}
try {
className = "org.springframework.web.reactive.socket.server.upgrade." + className;
Class<?> clazz = ClassUtils.forName(className, HandshakeWebSocketService.class.getClassLoader());
return (RequestUpgradeStrategy) ReflectionUtils.accessibleConstructor(clazz).newInstance();
}
catch (Throwable ex) {
throw new IllegalStateException(
"Failed to instantiate RequestUpgradeStrategy: " + className, ex);
}
}
/**
* Return the {@link RequestUpgradeStrategy} for WebSocket requests.
*/
public RequestUpgradeStrategy getUpgradeStrategy() {
return this.upgradeStrategy;
}
@Override
public boolean isRunning() {
return this.running;
}
@Override
public void start() {
if (!isRunning()) {
this.running = true;
doStart();
}
}
protected void doStart() {
if (getUpgradeStrategy() instanceof Lifecycle) {
((Lifecycle) getUpgradeStrategy()).start();
}
}
@Override
public void stop() {
if (isRunning()) {
this.running = false;
doStop();
}
}
protected void doStop() {
if (getUpgradeStrategy() instanceof Lifecycle) {
((Lifecycle) getUpgradeStrategy()).stop();
}
}
@Override
public Mono<Void> handleRequest(ServerWebExchange exchange, WebSocketHandler handler) {
ServerHttpRequest request = exchange.getRequest();
HttpMethod method = request.getMethod();
HttpHeaders headers = request.getHeaders();
if (logger.isDebugEnabled()) {
logger.debug("Handling " + request.getURI() + " with headers: " + headers);
}
if (HttpMethod.GET != method) {
return Mono.error(new MethodNotAllowedException(method, Collections.singleton(HttpMethod.GET)));
}
if (!"WebSocket".equalsIgnoreCase(headers.getUpgrade())) {
return handleBadRequest("Invalid 'Upgrade' header: " + headers);
}
List<String> connectionValue = headers.getConnection();
if (!connectionValue.contains("Upgrade") && !connectionValue.contains("upgrade")) {
return handleBadRequest("Invalid 'Connection' header: " + headers);
}
String key = headers.getFirst(SEC_WEBSOCKET_KEY);
if (key == null) {
return handleBadRequest("Missing \"Sec-WebSocket-Key\" header");
}
Optional<String> protocol = selectProtocol(headers, handler);
return this.upgradeStrategy.upgrade(exchange, handler, protocol);
}
private Mono<Void> handleBadRequest(String reason) {
if (logger.isDebugEnabled()) {
logger.debug(reason);
}
return Mono.error(new ServerWebInputException(reason));
}
private Optional<String> selectProtocol(HttpHeaders headers, WebSocketHandler handler) {
String protocolHeader = headers.getFirst(SEC_WEBSOCKET_PROTOCOL);
if (protocolHeader == null) {
return Optional.empty();
}
String[] protocols = handler.getSubProtocols();
return StringUtils.commaDelimitedListToSet(protocolHeader).stream()
.filter(protocol -> Arrays.stream(protocols).anyMatch(protocol::equals))
.findFirst();
}
}