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   1 /**
   2  * Copyright (c) 2010-2023 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.hpprinter.internal.api;
  14
  15 import java.io.IOException;
  16 import java.io.StringReader;
  17 import java.util.concurrent.ExecutionException;
  18 import java.util.concurrent.TimeUnit;
  19 import java.util.concurrent.TimeoutException;
  20 import java.util.function.Function;
  21
  22 import javax.xml.parsers.DocumentBuilder;
  23 import javax.xml.parsers.DocumentBuilderFactory;
  24 import javax.xml.parsers.ParserConfigurationException;
  25
  26 import org.eclipse.jdt.annotation.NonNullByDefault;
  27 import org.eclipse.jetty.client.HttpClient;
  28 import org.eclipse.jetty.client.api.ContentResponse;
  29 import org.eclipse.jetty.http.HttpMethod;
  30 import org.openhab.binding.hpprinter.internal.api.HPServerResult.RequestStatus;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33 import org.w3c.dom.Document;
  34 import org.xml.sax.InputSource;
  35 import org.xml.sax.SAXException;
  36
  37 /**
  38  * The {@link HPWebServerClient} is responsible for handling reading of data from the HP Embedded Web Server.
  39  *
  40  * @author Stewart Cossey - Initial contribution
  41  */
  42 @NonNullByDefault
  43 public class HPWebServerClient {
  44     public static final int REQUEST_TIMEOUT_SEC = 10;
  45     private final Logger logger = LoggerFactory.getLogger(HPWebServerClient.class);
  46
  47     private final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
  48     private final HttpClient httpClient;
  49     private final String serverAddress;
  50
  51     /**
  52      * Creates a new HP Web Server Client object.
  53      *
  54      * @param httpClient {HttpClient} The HttpClient to use for HTTP requests.
  55      * @param address The address for the Embedded Web Server.
  56      */
  57     public HPWebServerClient(HttpClient httpClient, String address) {
  58         this.httpClient = httpClient;
  59         serverAddress = "http://" + address;
  60
  61         logger.debug("Create printer connection {}", serverAddress);
  62     }
  63
  64     /**
  65      * Gets the Status information from the Embedded Web Server.
  66      *
  67      * @return The status information.
  68      */
  69     public HPServerResult<HPStatus> getStatus() {
  70         return fetchData(serverAddress + HPStatus.ENDPOINT, (HPStatus::new));
  71     }
  72
  73     public HPServerResult<HPProductUsageFeatures> getProductFeatures() {
  74         return fetchData(serverAddress + HPProductUsageFeatures.ENDPOINT, (HPProductUsageFeatures::new));
  75     }
  76
  77     public HPServerResult<HPFeatures> getProductUsageFeatures() {
  78         return fetchData(serverAddress + HPFeatures.ENDPOINT, (HPFeatures::new));
  79     }
  80
  81     public HPServerResult<HPScannerStatusFeatures> getScannerFeatures() {
  82         return fetchData(serverAddress + HPScannerStatusFeatures.ENDPOINT, (HPScannerStatusFeatures::new));
  83     }
  84
  85     /**
  86      * Gets the Usage information from the Embedded Web Server.
  87      *
  88      * @return The usage information.
  89      */
  90     public HPServerResult<HPUsage> getUsage() {
  91         return fetchData(serverAddress + HPUsage.ENDPOINT, (HPUsage::new));
  92     }
  93
  94     public HPServerResult<HPScannerStatus> getScannerStatus() {
  95         return fetchData(serverAddress + HPScannerStatus.ENDPOINT, (HPScannerStatus::new));
  96     }
  97
  98     public HPServerResult<HPProperties> getProperties() {
  99         return fetchData(serverAddress + HPProperties.ENDPOINT, (HPProperties::new));
 100     }
 101
 102     private <T> HPServerResult<T> fetchData(String endpoint, Function<Document, T> function) {
 103         try {
 104             logger.trace("HTTP Client Load {}", endpoint);
 105             ContentResponse cr = httpClient.newRequest(endpoint).method(HttpMethod.GET)
 106                     .timeout(REQUEST_TIMEOUT_SEC, TimeUnit.SECONDS).send();
 107
 108             String contentAsString = cr.getContentAsString();
 109             logger.trace("HTTP Client Result {} Size {}", cr.getStatus(), contentAsString.length());
 110             return new HPServerResult<>(function.apply(getDocument(contentAsString)));
 111         } catch (TimeoutException ex) {
 112             logger.trace("HTTP Client Timeout Exception {}", ex.getMessage());
 113             return new HPServerResult<>(RequestStatus.TIMEOUT, ex.getMessage());
 114         } catch (InterruptedException | ExecutionException | ParserConfigurationException | SAXException
 115                 | IOException ex) {
 116             logger.trace("HTTP Client Exception {}", ex.getMessage());
 117             return new HPServerResult<>(RequestStatus.ERROR, ex.getMessage());
 118         }
 119     }
 120
 121     private synchronized Document getDocument(String contentAsString)
 122             throws ParserConfigurationException, SAXException, IOException {
 123         // see https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html
 124         factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
 125         factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
 126         factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
 127         factory.setXIncludeAware(false);
 128         factory.setExpandEntityReferences(false);
 129         DocumentBuilder builder = factory.newDocumentBuilder();
 130         InputSource source = new InputSource(new StringReader(contentAsString));
 131         return builder.parse(source);
 132     }
 133 }