/*
* Copyright 2002-2014 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.socket.client.standard;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.URI;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.Callable;
import javax.websocket.ClientEndpointConfig;
import javax.websocket.ClientEndpointConfig.Configurator;
import javax.websocket.ContainerProvider;
import javax.websocket.Endpoint;
import javax.websocket.Extension;
import javax.websocket.HandshakeResponse;
import javax.websocket.WebSocketContainer;
import org.springframework.core.task.AsyncListenableTaskExecutor;
import org.springframework.core.task.SimpleAsyncTaskExecutor;
import org.springframework.core.task.TaskExecutor;
import org.springframework.http.HttpHeaders;
import org.springframework.lang.UsesJava7;
import org.springframework.util.Assert;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureTask;
import org.springframework.web.socket.WebSocketExtension;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter;
import org.springframework.web.socket.adapter.standard.StandardWebSocketSession;
import org.springframework.web.socket.adapter.standard.WebSocketToStandardExtensionAdapter;
import org.springframework.web.socket.client.AbstractWebSocketClient;
/**
* Initiates WebSocket requests to a WebSocket server programmatically
* through the standard Java WebSocket API.
*
* @author Rossen Stoyanchev
* @since 4.0
*/
public class StandardWebSocketClient extends AbstractWebSocketClient {
private final WebSocketContainer webSocketContainer;
private AsyncListenableTaskExecutor taskExecutor = new SimpleAsyncTaskExecutor();
/**
* Default constructor that calls {@code ContainerProvider.getWebSocketContainer()}
* to obtain a (new) {@link WebSocketContainer} instance. Also see constructor
* accepting existing {@code WebSocketContainer} instance.
*/
public StandardWebSocketClient() {
this.webSocketContainer = ContainerProvider.getWebSocketContainer();
}
/**
* Constructor accepting an existing {@link WebSocketContainer} instance.
* <p>For XML configuration, see {@link WebSocketContainerFactoryBean}. For Java
* configuration, use {@code ContainerProvider.getWebSocketContainer()} to obtain
* the {@code WebSocketContainer} instance.
*/
public StandardWebSocketClient(WebSocketContainer webSocketContainer) {
Assert.notNull(webSocketContainer, "WebSocketContainer must not be null");
this.webSocketContainer = webSocketContainer;
}
/**
* Set an {@link AsyncListenableTaskExecutor} to use when opening connections.
* If this property is set to {@code null}, calls to any of the
* {@code doHandshake} methods will block until the connection is established.
* <p>By default, an instance of {@code SimpleAsyncTaskExecutor} is used.
*/
public void setTaskExecutor(AsyncListenableTaskExecutor taskExecutor) {
this.taskExecutor = taskExecutor;
}
/**
* Return the configured {@link TaskExecutor}.
*/
public AsyncListenableTaskExecutor getTaskExecutor() {
return this.taskExecutor;
}
@Override
protected ListenableFuture<WebSocketSession> doHandshakeInternal(WebSocketHandler webSocketHandler,
HttpHeaders headers, final URI uri, List<String> protocols,
List<WebSocketExtension> extensions, Map<String, Object> attributes) {
int port = getPort(uri);
InetSocketAddress localAddress = new InetSocketAddress(getLocalHost(), port);
InetSocketAddress remoteAddress = new InetSocketAddress(uri.getHost(), port);
final StandardWebSocketSession session = new StandardWebSocketSession(headers,
attributes, localAddress, remoteAddress);
final ClientEndpointConfig.Builder configBuilder = ClientEndpointConfig.Builder.create();
configBuilder.configurator(new StandardWebSocketClientConfigurator(headers));
configBuilder.preferredSubprotocols(protocols);
configBuilder.extensions(adaptExtensions(extensions));
final Endpoint endpoint = new StandardWebSocketHandlerAdapter(webSocketHandler, session);
Callable<WebSocketSession> connectTask = new Callable<WebSocketSession>() {
@Override
public WebSocketSession call() throws Exception {
webSocketContainer.connectToServer(endpoint, configBuilder.build(), uri);
return session;
}
};
if (this.taskExecutor != null) {
return this.taskExecutor.submitListenable(connectTask);
}
else {
ListenableFutureTask<WebSocketSession> task = new ListenableFutureTask<WebSocketSession>(connectTask);
task.run();
return task;
}
}
private static List<Extension> adaptExtensions(List<WebSocketExtension> extensions) {
List<Extension> result = new ArrayList<Extension>();
for (WebSocketExtension extension : extensions) {
result.add(new WebSocketToStandardExtensionAdapter(extension));
}
return result;
}
@UsesJava7 // fallback to InetAddress.getLoopbackAddress()
private InetAddress getLocalHost() {
try {
return InetAddress.getLocalHost();
}
catch (UnknownHostException ex) {
return InetAddress.getLoopbackAddress();
}
}
private int getPort(URI uri) {
if (uri.getPort() == -1) {
String scheme = uri.getScheme().toLowerCase(Locale.ENGLISH);
return ("wss".equals(scheme) ? 443 : 80);
}
return uri.getPort();
}
private class StandardWebSocketClientConfigurator extends Configurator {
private final HttpHeaders headers;
public StandardWebSocketClientConfigurator(HttpHeaders headers) {
this.headers = headers;
}
@Override
public void beforeRequest(Map<String, List<String>> requestHeaders) {
requestHeaders.putAll(this.headers);
if (logger.isTraceEnabled()) {
logger.trace("Handshake request headers: " + requestHeaders);
}
}
@Override
public void afterResponse(HandshakeResponse response) {
if (logger.isTraceEnabled()) {
logger.trace("Handshake response headers: " + response.getHeaders());
}
}
}
}