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.InputStream;
009import java.net.HttpURLConnection;
010import java.util.ArrayList;
011import java.util.Collection;
012import java.util.Collections;
013import java.util.HashSet;
014import java.util.Iterator;
015import java.util.LinkedHashSet;
016import java.util.List;
017import java.util.Set;
018import java.util.concurrent.Callable;
019import java.util.concurrent.CompletionService;
020import java.util.concurrent.ExecutionException;
021import java.util.concurrent.ExecutorCompletionService;
022import java.util.concurrent.ExecutorService;
023import java.util.concurrent.Executors;
024import java.util.concurrent.Future;
025import java.util.stream.Collectors;
026
027import org.openstreetmap.josm.data.osm.DataSet;
028import org.openstreetmap.josm.data.osm.DataSetMerger;
029import org.openstreetmap.josm.data.osm.Node;
030import org.openstreetmap.josm.data.osm.OsmPrimitive;
031import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
032import org.openstreetmap.josm.data.osm.PrimitiveId;
033import org.openstreetmap.josm.data.osm.Relation;
034import org.openstreetmap.josm.data.osm.RelationMember;
035import org.openstreetmap.josm.data.osm.SimplePrimitiveId;
036import org.openstreetmap.josm.data.osm.Way;
037import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
038import org.openstreetmap.josm.gui.progress.ProgressMonitor;
039import org.openstreetmap.josm.spi.preferences.Config;
040import org.openstreetmap.josm.tools.Logging;
041import org.openstreetmap.josm.tools.Utils;
042
043/**
044 * Retrieves a set of {@link OsmPrimitive}s from an OSM server using the so called
045 * Multi Fetch API.
046 *
047 * Usage:
048 * <pre>
049 *    MultiFetchServerObjectReader reader = MultiFetchServerObjectReader()
050 *         .append(2345,2334,4444)
051 *         .append(new Node(72343));
052 *    reader.parseOsm();
053 *    if (!reader.getMissingPrimitives().isEmpty()) {
054 *        Logging.info("There are missing primitives: " + reader.getMissingPrimitives());
055 *    }
056 *    if (!reader.getSkippedWays().isEmpty()) {
057 *       Logging.info("There are skipped ways: " + reader.getMissingPrimitives());
058 *    }
059 * </pre>
060 */
061public class MultiFetchServerObjectReader extends OsmServerReader {
062    /**
063     * the max. number of primitives retrieved in one step. Assuming IDs with 10 digits,
064     * this leads to a max. request URL of ~ 1900 Bytes ((10 digits +  1 Separator) * 170),
065     * which should be safe according to the
066     * <a href="http://www.boutell.com/newfaq/misc/urllength.html">WWW FAQ</a>.
067     */
068    private static final int MAX_IDS_PER_REQUEST = 170;
069
070    private final Set<Long> nodes;
071    private final Set<Long> ways;
072    private final Set<Long> relations;
073    private Set<PrimitiveId> missingPrimitives;
074    private final DataSet outputDataSet;
075
076    /**
077     * Constructs a {@code MultiFetchServerObjectReader}.
078     */
079    protected MultiFetchServerObjectReader() {
080        nodes = new LinkedHashSet<>();
081        ways = new LinkedHashSet<>();
082        relations = new LinkedHashSet<>();
083        this.outputDataSet = new DataSet();
084        this.missingPrimitives = new LinkedHashSet<>();
085    }
086
087    /**
088     * Creates a new instance of {@link MultiFetchServerObjectReader} or {@link MultiFetchOverpassObjectReader}
089     * depending on the {@link OverpassDownloadReader#FOR_MULTI_FETCH preference}.
090     *
091     * @return a new instance
092     * @since 9241
093     */
094    public static MultiFetchServerObjectReader create() {
095        return create(OverpassDownloadReader.FOR_MULTI_FETCH.get());
096    }
097
098    /**
099     * Creates a new instance of {@link MultiFetchServerObjectReader} or {@link MultiFetchOverpassObjectReader}
100     * depending on the {@code fromMirror} parameter.
101     *
102     * @param fromMirror {@code false} for {@link MultiFetchServerObjectReader}, {@code true} for {@link MultiFetchOverpassObjectReader}
103     * @return a new instance
104     * @since 15520 (changed visibility)
105     */
106    public static MultiFetchServerObjectReader create(final boolean fromMirror) {
107        if (fromMirror) {
108            return new MultiFetchOverpassObjectReader();
109        } else {
110            return new MultiFetchServerObjectReader();
111        }
112    }
113
114    /**
115     * Remembers an {@link OsmPrimitive}'s id. The id will
116     * later be fetched as part of a Multi Get request.
117     *
118     * Ignore the id if it represents a new primitives.
119     *
120     * @param id  the id
121     */
122    protected void remember(PrimitiveId id) {
123        if (id.isNew()) return;
124        switch(id.getType()) {
125        case NODE: nodes.add(id.getUniqueId()); break;
126        case WAY: ways.add(id.getUniqueId()); break;
127        case RELATION: relations.add(id.getUniqueId()); break;
128        default: throw new AssertionError();
129        }
130    }
131
132    /**
133     * appends a {@link OsmPrimitive} id to the list of ids which will be fetched from the server.
134     *
135     * @param ds the {@link DataSet} to which the primitive belongs
136     * @param id the primitive id
137     * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
138     * {@link OsmPrimitiveType#RELATION RELATION}
139     * @return this
140     */
141    public MultiFetchServerObjectReader append(DataSet ds, long id, OsmPrimitiveType type) {
142        OsmPrimitive p = ds.getPrimitiveById(id, type);
143        switch(type) {
144        case NODE:
145            return appendNode((Node) p);
146        case WAY:
147            return appendWay((Way) p);
148        case RELATION:
149            return appendRelation((Relation) p);
150        default:
151            return this;
152        }
153    }
154
155    /**
156     * appends a {@link Node} id to the list of ids which will be fetched from the server.
157     *
158     * @param node  the node (ignored, if null)
159     * @return this
160     */
161    public MultiFetchServerObjectReader appendNode(Node node) {
162        if (node == null) return this;
163        remember(node.getPrimitiveId());
164        return this;
165    }
166
167    /**
168     * appends a {@link Way} id and the list of ids of nodes the way refers to the list of ids which will be fetched from the server.
169     *
170     * @param way the way (ignored, if null)
171     * @return this
172     */
173    public MultiFetchServerObjectReader appendWay(Way way) {
174        if (way == null) return this;
175        if (way.isNew()) return this;
176        for (Node node: !recursesDown() ? way.getNodes() : Collections.<Node>emptyList()) {
177            if (!node.isNew()) {
178                remember(node.getPrimitiveId());
179            }
180        }
181        remember(way.getPrimitiveId());
182        return this;
183    }
184
185    /**
186     * appends a {@link Relation} id to the list of ids which will be fetched from the server.
187     *
188     * @param relation  the relation (ignored, if null)
189     * @return this
190     */
191    protected MultiFetchServerObjectReader appendRelation(Relation relation) {
192        if (relation == null) return this;
193        if (relation.isNew()) return this;
194        remember(relation.getPrimitiveId());
195        for (RelationMember member : !recursesDown() ? relation.getMembers() : Collections.<RelationMember>emptyList()) {
196            // avoid infinite recursion in case of cyclic dependencies in relations
197            if (OsmPrimitiveType.from(member.getMember()) == OsmPrimitiveType.RELATION
198                    && relations.contains(member.getMember().getId())) {
199                continue;
200            }
201            if (!member.getMember().isIncomplete()) {
202                append(member.getMember());
203            }
204        }
205        return this;
206    }
207
208    /**
209     * appends an {@link OsmPrimitive} to the list of ids which will be fetched from the server.
210     * @param primitive the primitive
211     * @return this
212     */
213    public MultiFetchServerObjectReader append(OsmPrimitive primitive) {
214        if (primitive instanceof Node) {
215            return appendNode((Node) primitive);
216        } else if (primitive instanceof Way) {
217            return appendWay((Way) primitive);
218        } else if (primitive instanceof Relation) {
219            return appendRelation((Relation) primitive);
220        }
221        return this;
222    }
223
224    /**
225     * appends a list of {@link OsmPrimitive} to the list of ids which will be fetched from the server.
226     *
227     * @param primitives  the list of primitives (ignored, if null)
228     * @return this
229     *
230     * @see #append(OsmPrimitive)
231     */
232    public MultiFetchServerObjectReader append(Collection<? extends OsmPrimitive> primitives) {
233        if (primitives == null) return this;
234        for (OsmPrimitive primitive : primitives) {
235            append(primitive);
236        }
237        return this;
238    }
239
240    /**
241     * extracts a subset of max {@link #MAX_IDS_PER_REQUEST} ids from <code>ids</code> and
242     * replies the subset. The extracted subset is removed from <code>ids</code>.
243     *
244     * @param ids a set of ids
245     * @return the subset of ids
246     */
247    protected Set<Long> extractIdPackage(Set<Long> ids) {
248        Set<Long> pkg = new HashSet<>();
249        if (ids.isEmpty())
250            return pkg;
251        if (ids.size() > MAX_IDS_PER_REQUEST) {
252            Iterator<Long> it = ids.iterator();
253            for (int i = 0; i < MAX_IDS_PER_REQUEST; i++) {
254                pkg.add(it.next());
255            }
256            ids.removeAll(pkg);
257        } else {
258            pkg.addAll(ids);
259            ids.clear();
260        }
261        return pkg;
262    }
263
264    /**
265     * builds the Multi Get request string for a set of ids and a given {@link OsmPrimitiveType}.
266     *
267     * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
268     * {@link OsmPrimitiveType#RELATION RELATION}
269     * @param idPackage  the package of ids
270     * @return the request string
271     */
272    protected String buildRequestString(final OsmPrimitiveType type, Set<Long> idPackage) {
273        return type.getAPIName() + "s?" + type.getAPIName() + "s=" + idPackage.stream().map(String::valueOf).collect(Collectors.joining(","));
274    }
275
276    protected void rememberNodesOfIncompleteWaysToLoad(DataSet from) {
277        for (Way w: from.getWays()) {
278            if (w.hasIncompleteNodes()) {
279                for (Node n: w.getNodes()) {
280                    if (n.isIncomplete()) {
281                        nodes.add(n.getId());
282                    }
283                }
284            }
285        }
286    }
287
288    /**
289     * merges the dataset <code>from</code> to {@link #outputDataSet}.
290     *
291     * @param from the other dataset
292     */
293    protected void merge(DataSet from) {
294        final DataSetMerger visitor = new DataSetMerger(outputDataSet, from);
295        visitor.merge();
296    }
297
298    /**
299     * fetches a set of ids of a given {@link OsmPrimitiveType} from the server
300     *
301     * @param ids the set of ids
302     * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
303     * {@link OsmPrimitiveType#RELATION RELATION}
304     * @param progressMonitor progress monitor
305     * @throws OsmTransferException if an error occurs while communicating with the API server
306     */
307    protected void fetchPrimitives(Set<Long> ids, OsmPrimitiveType type, ProgressMonitor progressMonitor) throws OsmTransferException {
308        String msg;
309        final String baseUrl = getBaseUrl();
310        switch (type) {
311            // CHECKSTYLE.OFF: SingleSpaceSeparator
312            case NODE:     msg = tr("Fetching a package of nodes from ''{0}''",     baseUrl); break;
313            case WAY:      msg = tr("Fetching a package of ways from ''{0}''",      baseUrl); break;
314            case RELATION: msg = tr("Fetching a package of relations from ''{0}''", baseUrl); break;
315            // CHECKSTYLE.ON: SingleSpaceSeparator
316            default: throw new AssertionError();
317        }
318        progressMonitor.setTicksCount(ids.size());
319        progressMonitor.setTicks(0);
320        // The complete set containing all primitives to fetch
321        Set<Long> toFetch = new HashSet<>(ids);
322        // Build a list of fetchers that will  download smaller sets containing only MAX_IDS_PER_REQUEST (200) primitives each.
323        // we will run up to MAX_DOWNLOAD_THREADS concurrent fetchers.
324        int threadsNumber = Config.getPref().getInt("osm.download.threads", OsmApi.MAX_DOWNLOAD_THREADS);
325        threadsNumber = Utils.clamp(threadsNumber, 1, OsmApi.MAX_DOWNLOAD_THREADS);
326        final ExecutorService exec = Executors.newFixedThreadPool(
327                threadsNumber, Utils.newThreadFactory(getClass() + "-%d", Thread.NORM_PRIORITY));
328        CompletionService<FetchResult> ecs = new ExecutorCompletionService<>(exec);
329        List<Future<FetchResult>> jobs = new ArrayList<>();
330        while (!toFetch.isEmpty()) {
331            jobs.add(ecs.submit(new Fetcher(type, extractIdPackage(toFetch), progressMonitor)));
332        }
333        // Run the fetchers
334        for (int i = 0; i < jobs.size() && !isCanceled(); i++) {
335            progressMonitor.subTask(msg + "... " + progressMonitor.getTicks() + '/' + progressMonitor.getTicksCount());
336            try {
337                FetchResult result = ecs.take().get();
338                if (result.rc404 != null) {
339                    List<Long> toSplit = new ArrayList<>(result.rc404);
340                    int n = toSplit.size() / 2;
341                    jobs.add(ecs.submit(new Fetcher(type, new HashSet<>(toSplit.subList(0, n)), progressMonitor)));
342                    jobs.add(ecs.submit(new Fetcher(type, new HashSet<>(toSplit.subList(n, toSplit.size())), progressMonitor)));
343                }
344                if (result.missingPrimitives != null) {
345                    missingPrimitives.addAll(result.missingPrimitives);
346                }
347                if (result.dataSet != null && !isCanceled()) {
348                    rememberNodesOfIncompleteWaysToLoad(result.dataSet);
349                    merge(result.dataSet);
350                }
351            } catch (InterruptedException | ExecutionException e) {
352                Logging.error(e);
353            }
354        }
355        exec.shutdown();
356        // Cancel requests if the user chose to
357        if (isCanceled()) {
358            for (Future<FetchResult> job : jobs) {
359                job.cancel(true);
360            }
361        }
362    }
363
364    /**
365     * invokes one or more Multi Gets to fetch the {@link OsmPrimitive}s and replies
366     * the dataset of retrieved primitives. Note that the dataset includes non visible primitives too!
367     * In contrast to a simple Get for a node, a way, or a relation, a Multi Get always replies
368     * the latest version of the primitive (if any), even if the primitive is not visible (i.e. if
369     * visible==false).
370     *
371     * Invoke {@link #getMissingPrimitives()} to get a list of primitives which have not been
372     * found on  the server (the server response code was 404)
373     *
374     * @return the parsed data
375     * @throws OsmTransferException if an error occurs while communicating with the API server
376     * @see #getMissingPrimitives()
377     *
378     */
379    @Override
380    public DataSet parseOsm(ProgressMonitor progressMonitor) throws OsmTransferException {
381        int n = nodes.size() + ways.size() + relations.size();
382        progressMonitor.beginTask(trn("Downloading {0} object from ''{1}''",
383                "Downloading {0} objects from ''{1}''", n, n, OsmApi.getOsmApi().getBaseUrl()));
384        try {
385            missingPrimitives = new HashSet<>();
386            if (isCanceled()) return null;
387            fetchPrimitives(ways, OsmPrimitiveType.WAY, progressMonitor);
388            if (isCanceled()) return null;
389            fetchPrimitives(nodes, OsmPrimitiveType.NODE, progressMonitor);
390            if (isCanceled()) return null;
391            fetchPrimitives(relations, OsmPrimitiveType.RELATION, progressMonitor);
392            if (outputDataSet != null) {
393                outputDataSet.deleteInvisible();
394            }
395            return outputDataSet;
396        } finally {
397            progressMonitor.finishTask();
398        }
399    }
400
401    /**
402     * replies the set of ids of all primitives for which a fetch request to the
403     * server was submitted but which are not available from the server (the server
404     * replied a return code of 404)
405     *
406     * @return the set of ids of missing primitives
407     */
408    public Set<PrimitiveId> getMissingPrimitives() {
409        return missingPrimitives;
410    }
411
412    /**
413     * Whether this reader fetches nodes when loading ways, or members when loading relations.
414     *
415     * @return {@code true} if the reader recurses down
416     */
417    protected boolean recursesDown() {
418        return false;
419    }
420
421    /**
422     * The class holding the results given by {@link Fetcher}.
423     * It is only a wrapper of the resulting {@link DataSet} and the collection of {@link PrimitiveId} that could not have been loaded.
424     */
425    protected static class FetchResult {
426
427        /**
428         * The resulting data set
429         */
430        public final DataSet dataSet;
431
432        /**
433         * The collection of primitive ids that could not have been loaded
434         */
435        public final Set<PrimitiveId> missingPrimitives;
436
437        private Set<Long> rc404;
438
439        /**
440         * Constructs a {@code FetchResult}
441         * @param dataSet The resulting data set
442         * @param missingPrimitives The collection of primitive ids that could not have been loaded
443         */
444        public FetchResult(DataSet dataSet, Set<PrimitiveId> missingPrimitives) {
445            this.dataSet = dataSet;
446            this.missingPrimitives = missingPrimitives;
447        }
448    }
449
450    /**
451     * The class that actually download data from OSM API.
452     * Several instances of this class are used by {@link MultiFetchServerObjectReader} (one per set of primitives to fetch).
453     * The inheritance of {@link OsmServerReader} is only explained by the need to have a distinct OSM connection by {@code Fetcher} instance.
454     * @see FetchResult
455     */
456    protected class Fetcher extends OsmServerReader implements Callable<FetchResult> {
457
458        private final Set<Long> pkg;
459        private final OsmPrimitiveType type;
460        private final ProgressMonitor progressMonitor;
461
462        /**
463         * Constructs a {@code Fetcher}
464         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
465         * {@link OsmPrimitiveType#RELATION RELATION}
466         * @param idsPackage The set of primitives ids to fetch
467         * @param progressMonitor The progress monitor
468         */
469        public Fetcher(OsmPrimitiveType type, Set<Long> idsPackage, ProgressMonitor progressMonitor) {
470            this.pkg = idsPackage;
471            this.type = type;
472            this.progressMonitor = progressMonitor;
473        }
474
475        @Override
476        public DataSet parseOsm(ProgressMonitor progressMonitor) throws OsmTransferException {
477            // This method is implemented because of the OsmServerReader inheritance, but not used,
478            // as the main target of this class is the call() method.
479            return fetch(progressMonitor).dataSet;
480        }
481
482        @Override
483        public FetchResult call() throws Exception {
484            return fetch(progressMonitor);
485        }
486
487        /**
488         * fetches the requested primitives and updates the specified progress monitor.
489         * @param progressMonitor the progress monitor
490         * @return the {@link FetchResult} of this operation
491         * @throws OsmTransferException if an error occurs while communicating with the API server
492         */
493        protected FetchResult fetch(ProgressMonitor progressMonitor) throws OsmTransferException {
494            try {
495                return multiGetIdPackage(type, pkg, progressMonitor);
496            } catch (OsmApiException e) {
497                if (e.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
498                    if (pkg.size() > 4) {
499                        FetchResult res = new FetchResult(null, null);
500                        res.rc404 = pkg;
501                        return res;
502                    }
503                    Logging.info(tr("Server replied with response code 404, retrying with an individual request for each object."));
504                    return singleGetIdPackage(type, pkg, progressMonitor);
505                } else {
506                    throw e;
507                }
508            }
509        }
510
511        @Override
512        protected String getBaseUrl() {
513            return MultiFetchServerObjectReader.this.getBaseUrl();
514        }
515
516        /**
517         * invokes a Multi Get for a set of ids and a given {@link OsmPrimitiveType}.
518         * The retrieved primitives are merged to {@link #outputDataSet}.
519         *
520         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
521         * {@link OsmPrimitiveType#RELATION RELATION}
522         * @param pkg the package of ids
523         * @param progressMonitor progress monitor
524         * @return the {@link FetchResult} of this operation
525         * @throws OsmTransferException if an error occurs while communicating with the API server
526         */
527        protected FetchResult multiGetIdPackage(OsmPrimitiveType type, Set<Long> pkg, ProgressMonitor progressMonitor)
528                throws OsmTransferException {
529            String request = buildRequestString(type, pkg);
530            FetchResult result = null;
531            try (InputStream in = getInputStream(request, NullProgressMonitor.INSTANCE)) {
532                if (in == null) return null;
533                progressMonitor.subTask(tr("Downloading OSM data..."));
534                try {
535                    result = new FetchResult(OsmReader.parseDataSet(in, progressMonitor.createSubTaskMonitor(pkg.size(), false)), null);
536                } catch (IllegalDataException e) {
537                    throw new OsmTransferException(e);
538                }
539            } catch (IOException ex) {
540                Logging.warn(ex);
541            }
542            return result;
543        }
544
545        /**
546         * invokes a Multi Get for a single id and a given {@link OsmPrimitiveType}.
547         * The retrieved primitive is merged to {@link #outputDataSet}.
548         *
549         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
550         * {@link OsmPrimitiveType#RELATION RELATION}
551         * @param id the id
552         * @param progressMonitor progress monitor
553         * @return the {@link DataSet} resulting of this operation
554         * @throws OsmTransferException if an error occurs while communicating with the API server
555         */
556        protected DataSet singleGetId(OsmPrimitiveType type, long id, ProgressMonitor progressMonitor) throws OsmTransferException {
557            String request = buildRequestString(type, Collections.singleton(id));
558            DataSet result = null;
559            try (InputStream in = getInputStream(request, NullProgressMonitor.INSTANCE)) {
560                if (in == null) return null;
561                progressMonitor.subTask(tr("Downloading OSM data..."));
562                try {
563                    result = OsmReader.parseDataSet(in, progressMonitor.createSubTaskMonitor(1, false));
564                } catch (IllegalDataException e) {
565                    throw new OsmTransferException(e);
566                }
567            } catch (IOException ex) {
568                Logging.warn(ex);
569            }
570            return result;
571        }
572
573        /**
574         * invokes a sequence of Multi Gets for individual ids in a set of ids and a given {@link OsmPrimitiveType}.
575         * The retrieved primitives are merged to {@link #outputDataSet}.
576         *
577         * This method is used if one of the ids in pkg doesn't exist (the server replies with return code 404).
578         * If the set is fetched with this method it is possible to find out which of the ids doesn't exist.
579         * Unfortunately, the server does not provide an error header or an error body for a 404 reply.
580         *
581         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY},
582         * {@link OsmPrimitiveType#RELATION RELATION}
583         * @param pkg the set of ids
584         * @param progressMonitor progress monitor
585         * @return the {@link FetchResult} of this operation
586         * @throws OsmTransferException if an error occurs while communicating with the API server
587         */
588        protected FetchResult singleGetIdPackage(OsmPrimitiveType type, Set<Long> pkg, ProgressMonitor progressMonitor)
589                throws OsmTransferException {
590            FetchResult result = new FetchResult(new DataSet(), new HashSet<PrimitiveId>());
591            String baseUrl = OsmApi.getOsmApi().getBaseUrl();
592            for (long id : pkg) {
593                try {
594                    String msg;
595                    switch (type) {
596                        // CHECKSTYLE.OFF: SingleSpaceSeparator
597                        case NODE:     msg = tr("Fetching node with id {0} from ''{1}''",     id, baseUrl); break;
598                        case WAY:      msg = tr("Fetching way with id {0} from ''{1}''",      id, baseUrl); break;
599                        case RELATION: msg = tr("Fetching relation with id {0} from ''{1}''", id, baseUrl); break;
600                        // CHECKSTYLE.ON: SingleSpaceSeparator
601                        default: throw new AssertionError();
602                    }
603                    progressMonitor.setCustomText(msg);
604                    result.dataSet.mergeFrom(singleGetId(type, id, progressMonitor));
605                } catch (OsmApiException e) {
606                    if (e.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
607                        Logging.info(tr("Server replied with response code 404 for id {0}. Skipping.", Long.toString(id)));
608                        result.missingPrimitives.add(new SimplePrimitiveId(id, type));
609                    } else {
610                        throw e;
611                    }
612                }
613            }
614            return result;
615        }
616    }
617}