com.onthegomap.planetiler.util.Geofabrik Maven / Gradle / Ivy
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package com.onthegomap.planetiler.util;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.onthegomap.planetiler.config.PlanetilerConfig;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import javax.annotation.concurrent.Immutable;
import javax.annotation.concurrent.ThreadSafe;
/**
* A utility to search Geofabrik Download Server for a {@code .osm.pbf}
* download URL by name.
*
* @see Geofabrik JSON index technical details
*/
@ThreadSafe
public class Geofabrik {
private static volatile IndexJson index = null;
private static final ObjectMapper objectMapper = new ObjectMapper()
.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
/**
* Fetches the Geofabrik index and searches for a {@code .osm.pbf} resource to download where ID or name field
* contains all the tokens in {@code searchQuery}.
*
* If an exact match is found, returns that. Otherwise, looks for a resource that contains {@code searchQuery} as a
* substring.
*
* The index is only fetched once and cached after that.
*
* @param searchQuery the tokens to search for
* @param config planetiler config with user-agent and timeout to use when downloading files
* @return the URL of a {@code .osm.pbf} file with name or ID matching {@code searchQuery}
* @throws IllegalArgumentException if no matches, or more than one match is found.
*/
public static String getDownloadUrl(String searchQuery, PlanetilerConfig config) {
IndexJson index = getAndCacheIndex(config);
return searchIndexForDownloadUrl(searchQuery, index);
}
private static synchronized IndexJson getAndCacheIndex(PlanetilerConfig config) {
if (index == null) {
try (
InputStream inputStream = Downloader.openStream("https://download.geofabrik.de/index-v1-nogeom.json",
config)
) {
index = parseIndexJson(inputStream);
} catch (IOException e) {
throw new IllegalStateException(e);
}
}
return index;
}
private static Set tokenize(String in) {
return Stream.of(in.toLowerCase(Locale.ROOT).split("[^a-z]+")).collect(Collectors.toSet());
}
static IndexJson parseIndexJson(InputStream indexJsonContent) throws IOException {
return objectMapper.readValue(indexJsonContent, IndexJson.class);
}
static String searchIndexForDownloadUrl(String searchQuery, IndexJson index) {
Set searchTokens = tokenize(searchQuery);
List approxName = new ArrayList<>();
List id = new ArrayList<>();
List exactName = new ArrayList<>();
for (var feature : index.features) {
PropertiesJson properties = feature.properties;
if (properties.urls.containsKey("pbf")) {
if (properties.ids().stream().map(Geofabrik::tokenize).anyMatch(searchTokens::equals)) {
id.add(properties);
} else if (tokenize(properties.name).equals(searchTokens)) {
exactName.add(properties);
} else if (tokenize(properties.name).containsAll(searchTokens)) {
approxName.add(properties);
}
}
}
String result = getIfOnly(searchQuery, "exact ID matches", id);
if (result == null) {
result = getIfOnly(searchQuery, "exact name matches", exactName);
}
if (result == null) {
result = getIfOnly(searchQuery, "approximate name matches", approxName);
}
if (result == null) {
throw new IllegalArgumentException("No matches for '" + searchQuery + "'");
}
return result;
}
private static String getIfOnly(String name, String searchQuery, List values) {
if (values.size() > 1) {
throw new IllegalArgumentException(
"Multiple " + name + " for '" + searchQuery + "': " + values.stream().map(d -> d.id).collect(
Collectors.joining(", ")));
} else if (values.size() == 1) {
return values.getFirst().urls.get("pbf");
} else {
return null;
}
}
record PropertiesJson(String id, String parent, String name, Map urls,
@JsonProperty("iso3166-1:alpha2") List iso3166_1,
@JsonProperty("iso3166-2") List iso3166_2
) {
List ids() {
List result = new ArrayList<>(List.of(id, name));
if (iso3166_1 != null) {
result.addAll(iso3166_1);
}
if (iso3166_2 != null) {
result.addAll(iso3166_2);
}
return result;
}
}
record FeatureJson(PropertiesJson properties) {}
@Immutable
record IndexJson(List features) {}
}