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   1 /**
   2  * Copyright (c) 2010-2020 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.URI;
  16 import java.net.URISyntaxException;
  17 import java.util.Date;
  18 import java.util.List;
  19 import java.util.Optional;
  20 import java.util.Set;
  21 import java.util.concurrent.CompletableFuture;
  22 import java.util.concurrent.ConcurrentHashMap;
  23 import java.util.concurrent.ScheduledExecutorService;
  24 import java.util.concurrent.ScheduledFuture;
  25 import java.util.concurrent.TimeUnit;
  26 import java.util.function.Consumer;
  27
  28 import org.eclipse.jdt.annotation.NonNullByDefault;
  29 import org.eclipse.jdt.annotation.Nullable;
  30 import org.eclipse.jetty.client.HttpClient;
  31 import org.eclipse.jetty.client.api.Authentication;
  32 import org.eclipse.jetty.client.api.AuthenticationStore;
  33 import org.eclipse.jetty.client.api.Request;
  34 import org.openhab.binding.http.internal.Util;
  35 import org.openhab.binding.http.internal.config.HttpThingConfig;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 /**
  40  * The {@link RefreshingUrlCache} is responsible for requesting from a single URL and passing the content to the
  41  * channels
  42  *
  43  * @author Jan N. Klug - Initial contribution
  44  */
  45 @NonNullByDefault
  46 public class RefreshingUrlCache {
  47     private final Logger logger = LoggerFactory.getLogger(RefreshingUrlCache.class);
  48
  49     private final String url;
  50     private final HttpClient httpClient;
  51     private final int timeout;
  52     private final @Nullable String fallbackEncoding;
  53     private final Set<Consumer<Content>> consumers = ConcurrentHashMap.newKeySet();
  54     private final List<String> headers;
  55
  56     private final ScheduledFuture<?> future;
  57     private @Nullable Content lastContent;
  58
  59     public RefreshingUrlCache(ScheduledExecutorService executor, HttpClient httpClient, String url,
  60             HttpThingConfig thingConfig) {
  61         this.httpClient = httpClient;
  62         this.url = url;
  63         this.timeout = thingConfig.timeout;
  64         this.headers = thingConfig.headers;
  65         fallbackEncoding = thingConfig.encoding;
  66
  67         future = executor.scheduleWithFixedDelay(this::refresh, 0, 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 finalUrl = new URI(String.format(this.url, new Date()));
  84
  85             logger.trace("Requesting refresh (retry={}) from '{}' with timeout {}ms", isRetry, finalUrl, timeout);
  86             Request request = httpClient.newRequest(finalUrl).timeout(timeout, TimeUnit.MILLISECONDS);
  87
  88             headers.forEach(header -> {
  89                 String[] keyValuePair = header.split("=", 2);
  90                 if (keyValuePair.length == 2) {
  91                     request.header(keyValuePair[0].trim(), keyValuePair[1].trim());
  92                 } else {
  93                     logger.warn("Splitting header '{}' failed. No '=' was found. Ignoring", header);
  94                 }
  95             });
  96
  97             CompletableFuture<@Nullable Content> response = new CompletableFuture<>();
  98             response.exceptionally(e -> {
  99                 if (e instanceof HttpAuthException) {
 100                     if (isRetry) {
 101                         logger.warn("Retry after authentication  failure failed again for '{}', failing here",
 102                                 finalUrl);
 103                     } else {
 104                         AuthenticationStore authStore = httpClient.getAuthenticationStore();
 105                         Authentication.Result authResult = authStore.findAuthenticationResult(finalUrl);
 106                         if (authResult != null) {
 107                             authStore.removeAuthenticationResult(authResult);
 108                             logger.debug("Cleared authentication result for '{}', retrying immediately", finalUrl);
 109                             refresh(true);
 110                         } else {
 111                             logger.warn("Could not find authentication result for '{}', failing here", finalUrl);
 112                         }
 113                     }
 114                 }
 115                 return null;
 116             }).thenAccept(this::processResult);
 117
 118             if (logger.isTraceEnabled()) {
 119                 logger.trace("Sending to '{}': {}", finalUrl, Util.requestToLogString(request));
 120             }
 121
 122             request.send(new HttpResponseListener(response, fallbackEncoding));
 123         } catch (IllegalArgumentException | URISyntaxException e) {
 124             logger.warn("Creating request for '{}' failed: {}", url, e.getMessage());
 125         }
 126     }
 127
 128     public void stop() {
 129         // clearing all listeners to prevent further updates
 130         consumers.clear();
 131         future.cancel(false);
 132         logger.trace("Stopped refresh task for URL '{}'", url);
 133     }
 134
 135     public void addConsumer(Consumer<Content> consumer) {
 136         consumers.add(consumer);
 137     }
 138
 139     public Optional<Content> get() {
 140         final Content content = lastContent;
 141         if (content == null) {
 142             return Optional.empty();
 143         } else {
 144             return Optional.of(content);
 145         }
 146     }
 147
 148     private void processResult(@Nullable Content content) {
 149         if (content != null) {
 150             for (Consumer<Content> consumer : consumers) {
 151                 try {
 152                     consumer.accept(content);
 153                 } catch (IllegalArgumentException | IllegalStateException e) {
 154                     logger.warn("Failed processing result for URL {}: {}", url, e.getMessage());
 155                 }
 156             }
 157         }
 158         lastContent = content;
 159     }
 160 }