001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.io;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005import static org.openstreetmap.josm.tools.I18n.trn;
006
007import java.io.IOException;
008import java.io.PrintWriter;
009import java.io.StringReader;
010import java.io.StringWriter;
011import java.net.Authenticator.RequestorType;
012import java.net.ConnectException;
013import java.net.HttpURLConnection;
014import java.net.MalformedURLException;
015import java.net.SocketTimeoutException;
016import java.net.URL;
017import java.nio.charset.StandardCharsets;
018import java.util.Collection;
019import java.util.HashMap;
020import java.util.List;
021import java.util.Map;
022import java.util.function.Consumer;
023import java.util.function.UnaryOperator;
024
025import javax.xml.parsers.ParserConfigurationException;
026
027import org.openstreetmap.josm.data.coor.LatLon;
028import org.openstreetmap.josm.data.notes.Note;
029import org.openstreetmap.josm.data.osm.Changeset;
030import org.openstreetmap.josm.data.osm.IPrimitive;
031import org.openstreetmap.josm.data.osm.OsmPrimitive;
032import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
033import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
034import org.openstreetmap.josm.gui.progress.ProgressMonitor;
035import org.openstreetmap.josm.io.Capabilities.CapabilitiesParser;
036import org.openstreetmap.josm.io.auth.CredentialsManager;
037import org.openstreetmap.josm.spi.preferences.Config;
038import org.openstreetmap.josm.spi.preferences.IUrls;
039import org.openstreetmap.josm.tools.CheckParameterUtil;
040import org.openstreetmap.josm.tools.HttpClient;
041import org.openstreetmap.josm.tools.ListenerList;
042import org.openstreetmap.josm.tools.Logging;
043import org.openstreetmap.josm.tools.Utils;
044import org.openstreetmap.josm.tools.XmlParsingException;
045import org.xml.sax.InputSource;
046import org.xml.sax.SAXException;
047import org.xml.sax.SAXParseException;
048
049/**
050 * Class that encapsulates the communications with the <a href="http://wiki.openstreetmap.org/wiki/API_v0.6">OSM API</a>.<br><br>
051 *
052 * All interaction with the server-side OSM API should go through this class.<br><br>
053 *
054 * It is conceivable to extract this into an interface later and create various
055 * classes implementing the interface, to be able to talk to various kinds of servers.
056 * @since 1523
057 */
058public class OsmApi extends OsmConnection {
059
060    /**
061     * Maximum number of retries to send a request in case of HTTP 500 errors or timeouts
062     */
063    public static final int DEFAULT_MAX_NUM_RETRIES = 5;
064
065    /**
066     * Maximum number of concurrent download threads, imposed by
067     * <a href="http://wiki.openstreetmap.org/wiki/API_usage_policy#Technical_Usage_Requirements">
068     * OSM API usage policy.</a>
069     * @since 5386
070     */
071    public static final int MAX_DOWNLOAD_THREADS = 2;
072
073    /**
074     * Default URL of the standard OSM API.
075     * @deprecated Use {@link IUrls#getDefaultOsmApiUrl}
076     * @since 5422
077     */
078    @Deprecated
079    public static final String DEFAULT_API_URL = "https://api.openstreetmap.org/api";
080
081    // The collection of instantiated OSM APIs
082    private static final Map<String, OsmApi> instances = new HashMap<>();
083
084    private static final ListenerList<OsmApiInitializationListener> listeners = ListenerList.create();
085
086    private URL url;
087
088    /**
089     * OSM API initialization listener.
090     * @since 12804
091     */
092    public interface OsmApiInitializationListener {
093        /**
094         * Called when an OSM API instance has been successfully initialized.
095         * @param instance the initialized OSM API instance
096         */
097        void apiInitialized(OsmApi instance);
098    }
099
100    /**
101     * Adds a new OSM API initialization listener.
102     * @param listener OSM API initialization listener to add
103     * @since 12804
104     */
105    public static void addOsmApiInitializationListener(OsmApiInitializationListener listener) {
106        listeners.addListener(listener);
107    }
108
109    /**
110     * Removes an OSM API initialization listener.
111     * @param listener OSM API initialization listener to remove
112     * @since 12804
113     */
114    public static void removeOsmApiInitializationListener(OsmApiInitializationListener listener) {
115        listeners.removeListener(listener);
116    }
117
118    /**
119     * Replies the {@link OsmApi} for a given server URL
120     *
121     * @param serverUrl  the server URL
122     * @return the OsmApi
123     * @throws IllegalArgumentException if serverUrl is null
124     *
125     */
126    public static OsmApi getOsmApi(String serverUrl) {
127        OsmApi api = instances.get(serverUrl);
128        if (api == null) {
129            api = new OsmApi(serverUrl);
130            cacheInstance(api);
131        }
132        return api;
133    }
134
135    protected static void cacheInstance(OsmApi api) {
136        instances.put(api.getServerUrl(), api);
137    }
138
139    private static String getServerUrlFromPref() {
140        return Config.getPref().get("osm-server.url", Config.getUrls().getDefaultOsmApiUrl());
141    }
142
143    /**
144     * Replies the {@link OsmApi} for the URL given by the preference <code>osm-server.url</code>
145     *
146     * @return the OsmApi
147     */
148    public static OsmApi getOsmApi() {
149        return getOsmApi(getServerUrlFromPref());
150    }
151
152    /** Server URL */
153    private final String serverUrl;
154
155    /** Object describing current changeset */
156    private Changeset changeset;
157
158    /** API version used for server communications */
159    private String version;
160
161    /** API capabilities */
162    private Capabilities capabilities;
163
164    /** true if successfully initialized */
165    private boolean initialized;
166
167    /**
168     * Constructs a new {@code OsmApi} for a specific server URL.
169     *
170     * @param serverUrl the server URL. Must not be null
171     * @throws IllegalArgumentException if serverUrl is null
172     */
173    protected OsmApi(String serverUrl) {
174        CheckParameterUtil.ensureParameterNotNull(serverUrl, "serverUrl");
175        this.serverUrl = serverUrl;
176    }
177
178    /**
179     * Replies the OSM protocol version we use to talk to the server.
180     * @return protocol version, or null if not yet negotiated.
181     */
182    public String getVersion() {
183        return version;
184    }
185
186    /**
187     * Replies the host name of the server URL.
188     * @return the host name of the server URL, or null if the server URL is malformed.
189     */
190    public String getHost() {
191        String host = null;
192        try {
193            host = (new URL(serverUrl)).getHost();
194        } catch (MalformedURLException e) {
195            Logging.warn(e);
196        }
197        return host;
198    }
199
200    private class CapabilitiesCache extends CacheCustomContent<OsmTransferException> {
201
202        private static final String CAPABILITIES = "capabilities";
203
204        private final ProgressMonitor monitor;
205        private final boolean fastFail;
206
207        CapabilitiesCache(ProgressMonitor monitor, boolean fastFail) {
208            super(CAPABILITIES + getBaseUrl().hashCode(), CacheCustomContent.INTERVAL_WEEKLY);
209            this.monitor = monitor;
210            this.fastFail = fastFail;
211        }
212
213        @Override
214        protected void checkOfflineAccess() {
215            OnlineResource.OSM_API.checkOfflineAccess(getBaseUrl(getServerUrlFromPref(), "0.6")+CAPABILITIES, getServerUrlFromPref());
216        }
217
218        @Override
219        protected byte[] updateData() throws OsmTransferException {
220            return sendRequest("GET", CAPABILITIES, null, monitor, false, fastFail).getBytes(StandardCharsets.UTF_8);
221        }
222    }
223
224    /**
225     * Initializes this component by negotiating a protocol version with the server.
226     *
227     * @param monitor the progress monitor
228     * @throws OsmTransferCanceledException If the initialisation has been cancelled by user.
229     * @throws OsmApiInitializationException If any other exception occurs. Use getCause() to get the original exception.
230     */
231    public void initialize(ProgressMonitor monitor) throws OsmTransferCanceledException, OsmApiInitializationException {
232        initialize(monitor, false);
233    }
234
235    /**
236     * Initializes this component by negotiating a protocol version with the server, with the ability to control the timeout.
237     *
238     * @param monitor the progress monitor
239     * @param fastFail true to request quick initialisation with a small timeout (more likely to throw exception)
240     * @throws OsmTransferCanceledException If the initialisation has been cancelled by user.
241     * @throws OsmApiInitializationException If any other exception occurs. Use getCause() to get the original exception.
242     */
243    public void initialize(ProgressMonitor monitor, boolean fastFail) throws OsmTransferCanceledException, OsmApiInitializationException {
244        if (initialized)
245            return;
246        cancel = false;
247        try {
248            CapabilitiesCache cache = new CapabilitiesCache(monitor, fastFail);
249            try {
250                initializeCapabilities(cache.updateIfRequiredString());
251            } catch (SAXParseException parseException) {
252                Logging.trace(parseException);
253                // XML parsing may fail if JOSM previously stored a corrupted capabilities document (see #8278)
254                // In that case, force update and try again
255                initializeCapabilities(cache.updateForceString());
256            } catch (SecurityException e) {
257                Logging.log(Logging.LEVEL_ERROR, "Unable to initialize OSM API", e);
258            }
259            if (capabilities == null) {
260                if (NetworkManager.isOffline(OnlineResource.OSM_API)) {
261                    Logging.warn(tr("{0} not available (offline mode)", tr("OSM API")));
262                } else {
263                    Logging.error(tr("Unable to initialize OSM API."));
264                }
265                return;
266            } else if (!capabilities.supportsVersion("0.6")) {
267                Logging.error(tr("This version of JOSM is incompatible with the configured server."));
268                Logging.error(tr("It supports protocol version 0.6, while the server says it supports {0} to {1}.",
269                        capabilities.get("version", "minimum"), capabilities.get("version", "maximum")));
270                return;
271            } else {
272                version = "0.6";
273                initialized = true;
274            }
275
276            listeners.fireEvent(l -> l.apiInitialized(this));
277        } catch (OsmTransferCanceledException e) {
278            throw e;
279        } catch (OsmTransferException e) {
280            initialized = false;
281            NetworkManager.addNetworkError(url, Utils.getRootCause(e));
282            throw new OsmApiInitializationException(e);
283        } catch (SAXException | IOException | ParserConfigurationException e) {
284            initialized = false;
285            throw new OsmApiInitializationException(e);
286        }
287    }
288
289    private synchronized void initializeCapabilities(String xml) throws SAXException, IOException, ParserConfigurationException {
290        if (xml != null) {
291            capabilities = CapabilitiesParser.parse(new InputSource(new StringReader(xml)));
292        }
293    }
294
295    /**
296     * Makes an XML string from an OSM primitive. Uses the OsmWriter class.
297     * @param o the OSM primitive
298     * @param addBody true to generate the full XML, false to only generate the encapsulating tag
299     * @return XML string
300     */
301    protected final String toXml(IPrimitive o, boolean addBody) {
302        StringWriter swriter = new StringWriter();
303        try (OsmWriter osmWriter = OsmWriterFactory.createOsmWriter(new PrintWriter(swriter), true, version)) {
304            swriter.getBuffer().setLength(0);
305            osmWriter.setWithBody(addBody);
306            osmWriter.setChangeset(changeset);
307            osmWriter.header();
308            o.accept(osmWriter);
309            osmWriter.footer();
310            osmWriter.flush();
311        } catch (IOException e) {
312            Logging.warn(e);
313        }
314        return swriter.toString();
315    }
316
317    /**
318     * Makes an XML string from an OSM primitive. Uses the OsmWriter class.
319     * @param s the changeset
320     * @return XML string
321     */
322    protected final String toXml(Changeset s) {
323        StringWriter swriter = new StringWriter();
324        try (OsmWriter osmWriter = OsmWriterFactory.createOsmWriter(new PrintWriter(swriter), true, version)) {
325            swriter.getBuffer().setLength(0);
326            osmWriter.header();
327            osmWriter.visit(s);
328            osmWriter.footer();
329            osmWriter.flush();
330        } catch (IOException e) {
331            Logging.warn(e);
332        }
333        return swriter.toString();
334    }
335
336    private static String getBaseUrl(String serverUrl, String version) {
337        StringBuilder rv = new StringBuilder(serverUrl);
338        if (version != null) {
339            rv.append('/').append(version);
340        }
341        rv.append('/');
342        // this works around a ruby (or lighttpd) bug where two consecutive slashes in
343        // an URL will cause a "404 not found" response.
344        int p;
345        while ((p = rv.indexOf("//", rv.indexOf("://")+2)) > -1) {
346            rv.delete(p, p + 1);
347        }
348        return rv.toString();
349    }
350
351    /**
352     * Returns the base URL for API requests, including the negotiated version number.
353     * @return base URL string
354     */
355    public String getBaseUrl() {
356        return getBaseUrl(serverUrl, version);
357    }
358
359    /**
360     * Returns the server URL
361     * @return the server URL
362     * @since 9353
363     */
364    public String getServerUrl() {
365        return serverUrl;
366    }
367
368    private void individualPrimitiveModification(String method, String verb, IPrimitive osm, ProgressMonitor monitor,
369            Consumer<String> consumer, UnaryOperator<String> errHandler) throws OsmTransferException {
370        String ret = "";
371        try {
372            ensureValidChangeset();
373            initialize(monitor);
374            // Perform request
375            ret = sendRequest(method, OsmPrimitiveType.from(osm).getAPIName() + '/' + verb, toXml(osm, true), monitor);
376            // Unlock dataset if needed
377            boolean locked = false;
378            if (osm instanceof OsmPrimitive) {
379                locked = ((OsmPrimitive) osm).getDataSet().isLocked();
380                if (locked) {
381                    ((OsmPrimitive) osm).getDataSet().unlock();
382                }
383            }
384            try {
385                // Update local primitive
386                consumer.accept(ret);
387            } finally {
388                // Lock dataset back if needed
389                if (locked) {
390                    ((OsmPrimitive) osm).getDataSet().lock();
391                }
392            }
393        } catch (NumberFormatException e) {
394            throw new OsmTransferException(errHandler.apply(ret), e);
395        }
396    }
397
398    /**
399     * Creates an OSM primitive on the server. The OsmPrimitive object passed in
400     * is modified by giving it the server-assigned id.
401     *
402     * @param osm the primitive
403     * @param monitor the progress monitor
404     * @throws OsmTransferException if something goes wrong
405     */
406    public void createPrimitive(IPrimitive osm, ProgressMonitor monitor) throws OsmTransferException {
407        individualPrimitiveModification("PUT", "create", osm, monitor, ret -> {
408            osm.setOsmId(Long.parseLong(ret.trim()), 1);
409            osm.setChangesetId(getChangeset().getId());
410        }, ret -> tr("Unexpected format of ID replied by the server. Got ''{0}''.", ret));
411    }
412
413    /**
414     * Modifies an OSM primitive on the server.
415     *
416     * @param osm the primitive. Must not be null.
417     * @param monitor the progress monitor
418     * @throws OsmTransferException if something goes wrong
419     */
420    public void modifyPrimitive(IPrimitive osm, ProgressMonitor monitor) throws OsmTransferException {
421        individualPrimitiveModification("PUT", Long.toString(osm.getId()), osm, monitor, ret -> {
422            // API returns new object version
423            osm.setOsmId(osm.getId(), Integer.parseInt(ret.trim()));
424            osm.setChangesetId(getChangeset().getId());
425            osm.setVisible(true);
426        }, ret -> tr("Unexpected format of new version of modified primitive ''{0}''. Got ''{1}''.", osm.getId(), ret));
427    }
428
429    /**
430     * Deletes an OSM primitive on the server.
431     *
432     * @param osm the primitive
433     * @param monitor the progress monitor
434     * @throws OsmTransferException if something goes wrong
435     */
436    public void deletePrimitive(OsmPrimitive osm, ProgressMonitor monitor) throws OsmTransferException {
437        individualPrimitiveModification("DELETE", Long.toString(osm.getId()), osm, monitor, ret -> {
438            // API returns new object version
439            osm.setOsmId(osm.getId(), Integer.parseInt(ret.trim()));
440            osm.setChangesetId(getChangeset().getId());
441            osm.setVisible(false);
442        }, ret -> tr("Unexpected format of new version of deleted primitive ''{0}''. Got ''{1}''.", osm.getId(), ret));
443    }
444
445    /**
446     * Creates a new changeset based on the keys in <code>changeset</code>. If this
447     * method succeeds, changeset.getId() replies the id the server assigned to the new changeset
448     *
449     * The changeset must not be null, but its key/value-pairs may be empty.
450     *
451     * @param changeset the changeset toe be created. Must not be null.
452     * @param progressMonitor the progress monitor
453     * @throws OsmTransferException signifying a non-200 return code, or connection errors
454     * @throws IllegalArgumentException if changeset is null
455     */
456    public void openChangeset(Changeset changeset, ProgressMonitor progressMonitor) throws OsmTransferException {
457        CheckParameterUtil.ensureParameterNotNull(changeset, "changeset");
458        try {
459            progressMonitor.beginTask(tr("Creating changeset..."));
460            initialize(progressMonitor);
461            String ret = "";
462            try {
463                ret = sendRequest("PUT", "changeset/create", toXml(changeset), progressMonitor);
464                changeset.setId(Integer.parseInt(ret.trim()));
465                changeset.setOpen(true);
466            } catch (NumberFormatException e) {
467                throw new OsmTransferException(tr("Unexpected format of ID replied by the server. Got ''{0}''.", ret), e);
468            }
469            progressMonitor.setCustomText(tr("Successfully opened changeset {0}", changeset.getId()));
470        } finally {
471            progressMonitor.finishTask();
472        }
473    }
474
475    /**
476     * Updates a changeset with the keys in  <code>changesetUpdate</code>. The changeset must not
477     * be null and id &gt; 0 must be true.
478     *
479     * @param changeset the changeset to update. Must not be null.
480     * @param monitor the progress monitor. If null, uses the {@link NullProgressMonitor#INSTANCE}.
481     *
482     * @throws OsmTransferException if something goes wrong.
483     * @throws IllegalArgumentException if changeset is null
484     * @throws IllegalArgumentException if changeset.getId() &lt;= 0
485     *
486     */
487    public void updateChangeset(Changeset changeset, ProgressMonitor monitor) throws OsmTransferException {
488        CheckParameterUtil.ensureParameterNotNull(changeset, "changeset");
489        if (monitor == null) {
490            monitor = NullProgressMonitor.INSTANCE;
491        }
492        if (changeset.getId() <= 0)
493            throw new IllegalArgumentException(tr("Changeset ID > 0 expected. Got {0}.", changeset.getId()));
494        try {
495            monitor.beginTask(tr("Updating changeset..."));
496            initialize(monitor);
497            monitor.setCustomText(tr("Updating changeset {0}...", changeset.getId()));
498            sendRequest(
499                    "PUT",
500                    "changeset/" + changeset.getId(),
501                    toXml(changeset),
502                    monitor
503            );
504        } catch (ChangesetClosedException e) {
505            e.setSource(ChangesetClosedException.Source.UPDATE_CHANGESET);
506            throw e;
507        } catch (OsmApiException e) {
508            String errorHeader = e.getErrorHeader();
509            if (e.getResponseCode() == HttpURLConnection.HTTP_CONFLICT && ChangesetClosedException.errorHeaderMatchesPattern(errorHeader))
510                throw new ChangesetClosedException(errorHeader, ChangesetClosedException.Source.UPDATE_CHANGESET, e);
511            throw e;
512        } finally {
513            monitor.finishTask();
514        }
515    }
516
517    /**
518     * Closes a changeset on the server. Sets changeset.setOpen(false) if this operation succeeds.
519     *
520     * @param changeset the changeset to be closed. Must not be null. changeset.getId() &gt; 0 required.
521     * @param monitor the progress monitor. If null, uses {@link NullProgressMonitor#INSTANCE}
522     *
523     * @throws OsmTransferException if something goes wrong.
524     * @throws IllegalArgumentException if changeset is null
525     * @throws IllegalArgumentException if changeset.getId() &lt;= 0
526     */
527    public void closeChangeset(Changeset changeset, ProgressMonitor monitor) throws OsmTransferException {
528        CheckParameterUtil.ensureParameterNotNull(changeset, "changeset");
529        if (monitor == null) {
530            monitor = NullProgressMonitor.INSTANCE;
531        }
532        if (changeset.getId() <= 0)
533            throw new IllegalArgumentException(tr("Changeset ID > 0 expected. Got {0}.", changeset.getId()));
534        try {
535            monitor.beginTask(tr("Closing changeset..."));
536            initialize(monitor);
537            /* send "\r\n" instead of empty string, so we don't send zero payload - works around bugs
538               in proxy software */
539            sendRequest("PUT", "changeset" + "/" + changeset.getId() + "/close", "\r\n", monitor);
540            changeset.setOpen(false);
541        } finally {
542            monitor.finishTask();
543        }
544    }
545
546    /**
547     * Uploads a list of changes in "diff" form to the server.
548     *
549     * @param list the list of changed OSM Primitives
550     * @param  monitor the progress monitor
551     * @return list of processed primitives
552     * @throws OsmTransferException if something is wrong
553     */
554    public Collection<OsmPrimitive> uploadDiff(Collection<? extends OsmPrimitive> list, ProgressMonitor monitor)
555            throws OsmTransferException {
556        try {
557            monitor.beginTask("", list.size() * 2);
558            if (changeset == null)
559                throw new OsmTransferException(tr("No changeset present for diff upload."));
560
561            initialize(monitor);
562
563            // prepare upload request
564            //
565            OsmChangeBuilder changeBuilder = new OsmChangeBuilder(changeset);
566            monitor.subTask(tr("Preparing upload request..."));
567            changeBuilder.start();
568            changeBuilder.append(list);
569            changeBuilder.finish();
570            String diffUploadRequest = changeBuilder.getDocument();
571
572            // Upload to the server
573            //
574            monitor.indeterminateSubTask(
575                    trn("Uploading {0} object...", "Uploading {0} objects...", list.size(), list.size()));
576            String diffUploadResponse = sendRequest("POST", "changeset/" + changeset.getId() + "/upload", diffUploadRequest, monitor);
577
578            // Process the response from the server
579            //
580            DiffResultProcessor reader = new DiffResultProcessor(list);
581            reader.parse(diffUploadResponse, monitor.createSubTaskMonitor(ProgressMonitor.ALL_TICKS, false));
582            return reader.postProcess(
583                    getChangeset(),
584                    monitor.createSubTaskMonitor(ProgressMonitor.ALL_TICKS, false)
585            );
586        } catch (OsmTransferException e) {
587            throw e;
588        } catch (XmlParsingException e) {
589            throw new OsmTransferException(e);
590        } finally {
591            monitor.finishTask();
592        }
593    }
594
595    private void sleepAndListen(int retry, ProgressMonitor monitor) throws OsmTransferCanceledException {
596        Logging.info(tr("Waiting 10 seconds ... "));
597        for (int i = 0; i < 10; i++) {
598            if (monitor != null) {
599                monitor.setCustomText(tr("Starting retry {0} of {1} in {2} seconds ...", getMaxRetries() - retry, getMaxRetries(), 10-i));
600            }
601            if (cancel)
602                throw new OsmTransferCanceledException("Operation canceled" + (i > 0 ? " in retry #"+i : ""));
603            try {
604                Thread.sleep(1000);
605            } catch (InterruptedException ex) {
606                Logging.warn("InterruptedException in "+getClass().getSimpleName()+" during sleep");
607                Thread.currentThread().interrupt();
608            }
609        }
610        Logging.info(tr("OK - trying again."));
611    }
612
613    /**
614     * Replies the max. number of retries in case of 5XX errors on the server
615     *
616     * @return the max number of retries
617     */
618    protected int getMaxRetries() {
619        int ret = Config.getPref().getInt("osm-server.max-num-retries", DEFAULT_MAX_NUM_RETRIES);
620        return Math.max(ret, 0);
621    }
622
623    /**
624     * Determines if JOSM is configured to access OSM API via OAuth
625     * @return {@code true} if JOSM is configured to access OSM API via OAuth, {@code false} otherwise
626     * @since 6349
627     */
628    public static boolean isUsingOAuth() {
629        return "oauth".equals(getAuthMethod());
630    }
631
632    /**
633     * Returns the authentication method set in the preferences
634     * @return the authentication method
635     */
636    public static String getAuthMethod() {
637        return Config.getPref().get("osm-server.auth-method", "oauth");
638    }
639
640    protected final String sendRequest(String requestMethod, String urlSuffix, String requestBody, ProgressMonitor monitor)
641            throws OsmTransferException {
642        return sendRequest(requestMethod, urlSuffix, requestBody, monitor, true, false);
643    }
644
645    /**
646     * Generic method for sending requests to the OSM API.
647     *
648     * This method will automatically re-try any requests that are answered with a 5xx
649     * error code, or that resulted in a timeout exception from the TCP layer.
650     *
651     * @param requestMethod The http method used when talking with the server.
652     * @param urlSuffix The suffix to add at the server url, not including the version number,
653     *    but including any object ids (e.g. "/way/1234/history").
654     * @param requestBody the body of the HTTP request, if any.
655     * @param monitor the progress monitor
656     * @param doAuthenticate  set to true, if the request sent to the server shall include authentication
657     * credentials;
658     * @param fastFail true to request a short timeout
659     *
660     * @return the body of the HTTP response, if and only if the response code was "200 OK".
661     * @throws OsmTransferException if the HTTP return code was not 200 (and retries have
662     *    been exhausted), or rewrapping a Java exception.
663     */
664    protected final String sendRequest(String requestMethod, String urlSuffix, String requestBody, ProgressMonitor monitor,
665            boolean doAuthenticate, boolean fastFail) throws OsmTransferException {
666        int retries = fastFail ? 0 : getMaxRetries();
667
668        while (true) { // the retry loop
669            try {
670                url = new URL(new URL(getBaseUrl()), urlSuffix);
671                final HttpClient client = HttpClient.create(url, requestMethod).keepAlive(false);
672                activeConnection = client;
673                if (fastFail) {
674                    client.setConnectTimeout(1000);
675                    client.setReadTimeout(1000);
676                } else {
677                    // use default connect timeout from org.openstreetmap.josm.tools.HttpClient.connectTimeout
678                    client.setReadTimeout(0);
679                }
680                if (doAuthenticate) {
681                    addAuth(client);
682                }
683
684                if ("PUT".equals(requestMethod) || "POST".equals(requestMethod) || "DELETE".equals(requestMethod)) {
685                    client.setHeader("Content-Type", "text/xml");
686                    // It seems that certain bits of the Ruby API are very unhappy upon
687                    // receipt of a PUT/POST message without a Content-length header,
688                    // even if the request has no payload.
689                    // Since Java will not generate a Content-length header unless
690                    // we use the output stream, we create an output stream for PUT/POST
691                    // even if there is no payload.
692                    client.setRequestBody((requestBody != null ? requestBody : "").getBytes(StandardCharsets.UTF_8));
693                }
694
695                final HttpClient.Response response = client.connect();
696                Logging.info(response.getResponseMessage());
697                int retCode = response.getResponseCode();
698
699                if (retCode >= 500 && retries-- > 0) {
700                    sleepAndListen(retries, monitor);
701                    Logging.info(tr("Starting retry {0} of {1}.", getMaxRetries() - retries, getMaxRetries()));
702                    continue;
703                }
704
705                final String responseBody = response.fetchContent();
706
707                String errorHeader = null;
708                // Look for a detailed error message from the server
709                if (response.getHeaderField("Error") != null) {
710                    errorHeader = response.getHeaderField("Error");
711                    Logging.error("Error header: " + errorHeader);
712                } else if (retCode != HttpURLConnection.HTTP_OK && responseBody.length() > 0) {
713                    Logging.error("Error body: " + responseBody);
714                }
715                activeConnection.disconnect();
716
717                errorHeader = errorHeader == null ? null : errorHeader.trim();
718                String errorBody = responseBody.length() == 0 ? null : responseBody.trim();
719                switch(retCode) {
720                case HttpURLConnection.HTTP_OK:
721                    return responseBody;
722                case HttpURLConnection.HTTP_GONE:
723                    throw new OsmApiPrimitiveGoneException(errorHeader, errorBody);
724                case HttpURLConnection.HTTP_CONFLICT:
725                    if (ChangesetClosedException.errorHeaderMatchesPattern(errorHeader))
726                        throw new ChangesetClosedException(errorBody, ChangesetClosedException.Source.UPLOAD_DATA);
727                    else
728                        throw new OsmApiException(retCode, errorHeader, errorBody);
729                case HttpURLConnection.HTTP_UNAUTHORIZED:
730                case HttpURLConnection.HTTP_FORBIDDEN:
731                    CredentialsManager.getInstance().purgeCredentialsCache(RequestorType.SERVER);
732                    throw new OsmApiException(retCode, errorHeader, errorBody, activeConnection.getURL().toString(),
733                            doAuthenticate ? retrieveBasicAuthorizationLogin(client) : null, response.getContentType());
734                default:
735                    throw new OsmApiException(retCode, errorHeader, errorBody);
736                }
737            } catch (SocketTimeoutException | ConnectException e) {
738                if (retries-- > 0) {
739                    continue;
740                }
741                throw new OsmTransferException(e);
742            } catch (IOException e) {
743                throw new OsmTransferException(e);
744            } catch (OsmTransferException e) {
745                throw e;
746            }
747        }
748    }
749
750    /**
751     * Replies the API capabilities.
752     *
753     * @return the API capabilities, or null, if the API is not initialized yet
754     */
755    public synchronized Capabilities getCapabilities() {
756        return capabilities;
757    }
758
759    /**
760     * Ensures that the current changeset can be used for uploading data
761     *
762     * @throws OsmTransferException if the current changeset can't be used for uploading data
763     */
764    protected void ensureValidChangeset() throws OsmTransferException {
765        if (changeset == null)
766            throw new OsmTransferException(tr("Current changeset is null. Cannot upload data."));
767        if (changeset.getId() <= 0)
768            throw new OsmTransferException(tr("ID of current changeset > 0 required. Current ID is {0}.", changeset.getId()));
769    }
770
771    /**
772     * Replies the changeset data uploads are currently directed to
773     *
774     * @return the changeset data uploads are currently directed to
775     */
776    public Changeset getChangeset() {
777        return changeset;
778    }
779
780    /**
781     * Sets the changesets to which further data uploads are directed. The changeset
782     * can be null. If it isn't null it must have been created, i.e. id &gt; 0 is required. Furthermore,
783     * it must be open.
784     *
785     * @param changeset the changeset
786     * @throws IllegalArgumentException if changeset.getId() &lt;= 0
787     * @throws IllegalArgumentException if !changeset.isOpen()
788     */
789    public void setChangeset(Changeset changeset) {
790        if (changeset == null) {
791            this.changeset = null;
792            return;
793        }
794        if (changeset.getId() <= 0)
795            throw new IllegalArgumentException(tr("Changeset ID > 0 expected. Got {0}.", changeset.getId()));
796        if (!changeset.isOpen())
797            throw new IllegalArgumentException(tr("Open changeset expected. Got closed changeset with id {0}.", changeset.getId()));
798        this.changeset = changeset;
799    }
800
801    private static StringBuilder noteStringBuilder(Note note) {
802        return new StringBuilder().append("notes/").append(note.getId());
803    }
804
805    /**
806     * Create a new note on the server.
807     * @param latlon Location of note
808     * @param text Comment entered by user to open the note
809     * @param monitor Progress monitor
810     * @return Note as it exists on the server after creation (ID assigned)
811     * @throws OsmTransferException if any error occurs during dialog with OSM API
812     */
813    public Note createNote(LatLon latlon, String text, ProgressMonitor monitor) throws OsmTransferException {
814        initialize(monitor);
815        String noteUrl = new StringBuilder()
816            .append("notes?lat=")
817            .append(latlon.lat())
818            .append("&lon=")
819            .append(latlon.lon())
820            .append("&text=")
821            .append(Utils.encodeUrl(text)).toString();
822
823        String response = sendRequest("POST", noteUrl, null, monitor, true, false);
824        return parseSingleNote(response);
825    }
826
827    /**
828     * Add a comment to an existing note.
829     * @param note The note to add a comment to
830     * @param comment Text of the comment
831     * @param monitor Progress monitor
832     * @return Note returned by the API after the comment was added
833     * @throws OsmTransferException if any error occurs during dialog with OSM API
834     */
835    public Note addCommentToNote(Note note, String comment, ProgressMonitor monitor) throws OsmTransferException {
836        initialize(monitor);
837        String noteUrl = noteStringBuilder(note)
838            .append("/comment?text=")
839            .append(Utils.encodeUrl(comment)).toString();
840
841        String response = sendRequest("POST", noteUrl, null, monitor, true, false);
842        return parseSingleNote(response);
843    }
844
845    /**
846     * Close a note.
847     * @param note Note to close. Must currently be open
848     * @param closeMessage Optional message supplied by the user when closing the note
849     * @param monitor Progress monitor
850     * @return Note returned by the API after the close operation
851     * @throws OsmTransferException if any error occurs during dialog with OSM API
852     */
853    public Note closeNote(Note note, String closeMessage, ProgressMonitor monitor) throws OsmTransferException {
854        initialize(monitor);
855        String encodedMessage = Utils.encodeUrl(closeMessage);
856        StringBuilder urlBuilder = noteStringBuilder(note)
857            .append("/close");
858        if (!encodedMessage.trim().isEmpty()) {
859            urlBuilder.append("?text=");
860            urlBuilder.append(encodedMessage);
861        }
862
863        String response = sendRequest("POST", urlBuilder.toString(), null, monitor, true, false);
864        return parseSingleNote(response);
865    }
866
867    /**
868     * Reopen a closed note
869     * @param note Note to reopen. Must currently be closed
870     * @param reactivateMessage Optional message supplied by the user when reopening the note
871     * @param monitor Progress monitor
872     * @return Note returned by the API after the reopen operation
873     * @throws OsmTransferException if any error occurs during dialog with OSM API
874     */
875    public Note reopenNote(Note note, String reactivateMessage, ProgressMonitor monitor) throws OsmTransferException {
876        initialize(monitor);
877        String encodedMessage = Utils.encodeUrl(reactivateMessage);
878        StringBuilder urlBuilder = noteStringBuilder(note)
879            .append("/reopen");
880        if (!encodedMessage.trim().isEmpty()) {
881            urlBuilder.append("?text=");
882            urlBuilder.append(encodedMessage);
883        }
884
885        String response = sendRequest("POST", urlBuilder.toString(), null, monitor, true, false);
886        return parseSingleNote(response);
887    }
888
889    /**
890     * Method for parsing API responses for operations on individual notes
891     * @param xml the API response as XML data
892     * @return the resulting Note
893     * @throws OsmTransferException if the API response cannot be parsed
894     */
895    private static Note parseSingleNote(String xml) throws OsmTransferException {
896        try {
897            List<Note> newNotes = new NoteReader(xml).parse();
898            if (newNotes.size() == 1) {
899                return newNotes.get(0);
900            }
901            // Shouldn't ever execute. Server will either respond with an error (caught elsewhere) or one note
902            throw new OsmTransferException(tr("Note upload failed"));
903        } catch (SAXException | IOException e) {
904            Logging.error(e);
905            throw new OsmTransferException(tr("Error parsing note response from server"), e);
906        }
907    }
908}