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   1 /**
   2  * Copyright (c) 2010-2021 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.http.internal.http;
  14
  15 import java.net.*;
  16 import java.util.Date;
  17 import java.util.List;
  18 import java.util.Optional;
  19 import java.util.Set;
  20 import java.util.concurrent.*;
  21 import java.util.function.Consumer;
  22
  23 import org.eclipse.jdt.annotation.NonNullByDefault;
  24 import org.eclipse.jdt.annotation.Nullable;
  25 import org.eclipse.jetty.client.api.Authentication;
  26 import org.eclipse.jetty.client.api.AuthenticationStore;
  27 import org.eclipse.jetty.http.HttpMethod;
  28 import org.openhab.binding.http.internal.Util;
  29 import org.openhab.binding.http.internal.config.HttpThingConfig;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 /**
  34  * The {@link RefreshingUrlCache} is responsible for requesting from a single URL and passing the content to the
  35  * channels
  36  *
  37  * @author Jan N. Klug - Initial contribution
  38  */
  39 @NonNullByDefault
  40 public class RefreshingUrlCache {
  41     private final Logger logger = LoggerFactory.getLogger(RefreshingUrlCache.class);
  42
  43     private final String url;
  44     private final RateLimitedHttpClient httpClient;
  45     private final int timeout;
  46     private final int bufferSize;
  47     private final @Nullable String fallbackEncoding;
  48     private final Set<Consumer<Content>> consumers = ConcurrentHashMap.newKeySet();
  49     private final List<String> headers;
  50     private final HttpMethod httpMethod;
  51     private final String httpContent;
  52
  53     private final ScheduledFuture<?> future;
  54     private @Nullable Content lastContent;
  55
  56     public RefreshingUrlCache(ScheduledExecutorService executor, RateLimitedHttpClient httpClient, String url,
  57             HttpThingConfig thingConfig, String httpContent) {
  58         this.httpClient = httpClient;
  59         this.url = url;
  60         this.timeout = thingConfig.timeout;
  61         this.bufferSize = thingConfig.bufferSize;
  62         this.headers = thingConfig.headers;
  63         this.httpMethod = thingConfig.stateMethod;
  64         this.httpContent = httpContent;
  65         fallbackEncoding = thingConfig.encoding;
  66
  67         future = executor.scheduleWithFixedDelay(this::refresh, 1, thingConfig.refresh, TimeUnit.SECONDS);
  68         logger.trace("Started refresh task for URL '{}' with interval {}s", url, thingConfig.refresh);
  69     }
  70
  71     private void refresh() {
  72         refresh(false);
  73     }
  74
  75     private void refresh(boolean isRetry) {
  76         if (consumers.isEmpty()) {
  77             // do not refresh if we don't have listeners
  78             return;
  79         }
  80
  81         // format URL
  82         try {
  83             URI uri = Util.uriFromString(String.format(this.url, new Date()));
  84             logger.trace("Requesting refresh (retry={}) from '{}' with timeout {}ms", isRetry, uri, timeout);
  85
  86             httpClient.newRequest(uri, httpMethod, httpContent).thenAccept(request -> {
  87                 request.timeout(timeout, TimeUnit.MILLISECONDS);
  88
  89                 headers.forEach(header -> {
  90                     String[] keyValuePair = header.split("=", 2);
  91                     if (keyValuePair.length == 2) {
  92                         request.header(keyValuePair[0].trim(), keyValuePair[1].trim());
  93                     } else {
  94                         logger.warn("Splitting header '{}' failed. No '=' was found. Ignoring", header);
  95                     }
  96                 });
  97
  98                 CompletableFuture<@Nullable Content> response = new CompletableFuture<>();
  99                 response.exceptionally(e -> {
 100                     if (e instanceof HttpAuthException) {
 101                         if (isRetry) {
 102                             logger.warn("Retry after authentication failure failed again for '{}', failing here", uri);
 103                         } else {
 104                             AuthenticationStore authStore = httpClient.getAuthenticationStore();
 105                             Authentication.Result authResult = authStore.findAuthenticationResult(uri);
 106                             if (authResult != null) {
 107                                 authStore.removeAuthenticationResult(authResult);
 108                                 logger.debug("Cleared authentication result for '{}', retrying immediately", uri);
 109                                 refresh(true);
 110                             } else {
 111                                 logger.warn("Could not find authentication result for '{}', failing here", uri);
 112                             }
 113                         }
 114                     }
 115                     return null;
 116                 }).thenAccept(this::processResult);
 117
 118                 if (logger.isTraceEnabled()) {
 119                     logger.trace("Sending to '{}': {}", uri, Util.requestToLogString(request));
 120                 }
 121
 122                 request.send(new HttpResponseListener(response, fallbackEncoding, bufferSize));
 123             }).exceptionally(e -> {
 124                 if (e instanceof CancellationException) {
 125                     logger.debug("Request to URL {} was cancelled by thing handler.", uri);
 126                 } else {
 127                     logger.warn("Request to URL {} failed: {}", uri, e.getMessage());
 128                 }
 129                 return null;
 130             });
 131         } catch (IllegalArgumentException | URISyntaxException | MalformedURLException e) {
 132             logger.warn("Creating request for '{}' failed: {}", url, e.getMessage());
 133         }
 134     }
 135
 136     public void stop() {
 137         // clearing all listeners to prevent further updates
 138         consumers.clear();
 139         future.cancel(false);
 140         logger.trace("Stopped refresh task for URL '{}'", url);
 141     }
 142
 143     public void addConsumer(Consumer<Content> consumer) {
 144         consumers.add(consumer);
 145     }
 146
 147     public Optional<Content> get() {
 148         final Content content = lastContent;
 149         if (content == null) {
 150             return Optional.empty();
 151         } else {
 152             return Optional.of(content);
 153         }
 154     }
 155
 156     private void processResult(@Nullable Content content) {
 157         if (content != null) {
 158             for (Consumer<Content> consumer : consumers) {
 159                 try {
 160                     consumer.accept(content);
 161                 } catch (IllegalArgumentException | IllegalStateException e) {
 162                     logger.warn("Failed processing result for URL {}: {}", url, e.getMessage());
 163                 }
 164             }
 165         }
 166         lastContent = content;
 167     }
 168 }