org.springframework.web.socket.client.endpoint.StandardWebSocketClient.java Source code

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Here is the source code for org.springframework.web.socket.client.endpoint.StandardWebSocketClient.java

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/*
 * Copyright 2002-2013 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.endpoint;

import java.net.URI;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.websocket.ClientEndpointConfig;
import javax.websocket.ClientEndpointConfig.Configurator;
import javax.websocket.ContainerProvider;
import javax.websocket.Endpoint;
import javax.websocket.HandshakeResponse;
import javax.websocket.WebSocketContainer;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.util.Assert;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.adapter.StandardEndpointAdapter;
import org.springframework.web.socket.adapter.StandardWebSocketSessionAdapter;
import org.springframework.web.socket.client.WebSocketClient;
import org.springframework.web.socket.client.WebSocketConnectFailureException;
import org.springframework.web.util.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;

/**
 * Initiates WebSocket requests to a WebSocket server programatically through the standard
 * Java WebSocket API .
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public class StandardWebSocketClient implements WebSocketClient {

    private static final Log logger = LogFactory.getLog(StandardWebSocketClient.class);

    private final WebSocketContainer webSocketContainer;

    public StandardWebSocketClient() {
        this.webSocketContainer = ContainerProvider.getWebSocketContainer();
    }

    public StandardWebSocketClient(WebSocketContainer webSocketContainer) {
        Assert.notNull(webSocketContainer, "webSocketContainer is required");
        this.webSocketContainer = webSocketContainer;
    }

    @Override
    public WebSocketSession doHandshake(WebSocketHandler webSocketHandler, String uriTemplate,
            Object... uriVariables) throws WebSocketConnectFailureException {

        Assert.notNull(uriTemplate, "uriTemplate is required");
        UriComponents uriComponents = UriComponentsBuilder.fromUriString(uriTemplate).buildAndExpand(uriVariables)
                .encode();
        return doHandshake(webSocketHandler, null, uriComponents.toUri());
    }

    @Override
    public WebSocketSession doHandshake(WebSocketHandler webSocketHandler, HttpHeaders httpHeaders, URI uri)
            throws WebSocketConnectFailureException {

        Assert.notNull(webSocketHandler, "webSocketHandler is required");
        Assert.notNull(uri, "uri is required");

        httpHeaders = (httpHeaders != null) ? httpHeaders : new HttpHeaders();

        if (logger.isDebugEnabled()) {
            logger.debug("Connecting to " + uri);
        }

        StandardWebSocketSessionAdapter session = new StandardWebSocketSessionAdapter();
        session.setUri(uri);
        session.setRemoteHostName(uri.getHost());

        ClientEndpointConfig.Builder configBuidler = ClientEndpointConfig.Builder.create();
        configBuidler.configurator(new StandardWebSocketClientConfigurator(httpHeaders));

        List<String> protocols = httpHeaders.getSecWebSocketProtocol();
        if (!protocols.isEmpty()) {
            configBuidler.preferredSubprotocols(protocols);
        }

        try {
            // TODO: do not block
            Endpoint endpoint = new StandardEndpointAdapter(webSocketHandler, session);
            this.webSocketContainer.connectToServer(endpoint, configBuidler.build(), uri);

            return session;
        } catch (Exception e) {
            throw new WebSocketConnectFailureException("Failed to connect to " + uri, e);
        }
    }

    private static class StandardWebSocketClientConfigurator extends Configurator {

        private static final Set<String> EXCLUDED_HEADERS = new HashSet<String>(
                Arrays.asList("Sec-WebSocket-Accept", "Sec-WebSocket-Extensions", "Sec-WebSocket-Key",
                        "Sec-WebSocket-Protocol", "Sec-WebSocket-Version"));

        private final HttpHeaders httpHeaders;

        public StandardWebSocketClientConfigurator(HttpHeaders httpHeaders) {
            this.httpHeaders = httpHeaders;
        }

        @Override
        public void beforeRequest(Map<String, List<String>> headers) {
            for (String headerName : this.httpHeaders.keySet()) {
                if (!EXCLUDED_HEADERS.contains(headerName)) {
                    List<String> value = this.httpHeaders.get(headerName);
                    if (logger.isTraceEnabled()) {
                        logger.trace("Adding header [" + headerName + "=" + value + "]");
                    }
                    headers.put(headerName, value);
                }
            }
            if (logger.isDebugEnabled()) {
                logger.debug("Handshake request headers: " + headers);
            }
        }

        @Override
        public void afterResponse(HandshakeResponse handshakeResponse) {
            if (logger.isDebugEnabled()) {
                logger.debug("Handshake response headers: " + handshakeResponse.getHeaders());
            }
        }
    }

}