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