com.arangodb.springframework.repository.query.ArangoResultConverter Maven / Gradle / Ivy
/*
* DISCLAIMER
*
* Copyright 2017 ArangoDB GmbH, Cologne, Germany
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright holder is ArangoDB GmbH, Cologne, Germany
*/
package com.arangodb.springframework.repository.query;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.Spliterators;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.Slice;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoPage;
import org.springframework.data.geo.GeoResult;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.geo.Metrics;
import org.springframework.util.Assert;
import com.arangodb.ArangoCursor;
import com.arangodb.springframework.core.ArangoOperations;
import com.arangodb.velocypack.VPackSlice;
/**
* Converts the result returned from the ArangoDB Java driver to the desired type.
*
* @author Audrius Malele
* @author Mark McCormick
* @author Mark Vollmary
* @author Christian Lechner
*/
public class ArangoResultConverter {
private final static String MISSING_FULL_COUNT = "Query result does not contain the full result count! "
+ "The most likely cause is a forgotten LIMIT clause in the query.";
private final ArangoParameterAccessor accessor;
private final ArangoCursor result;
private final ArangoOperations operations;
private final Class domainClass;
private static Map TYPE_MAP = new HashMap<>();
/**
* Build static map of all supported return types and the method used to convert them
*/
static {
try {
TYPE_MAP.put(List.class, ArangoResultConverter.class.getMethod("convertList"));
TYPE_MAP.put(Iterable.class, ArangoResultConverter.class.getMethod("convertList"));
TYPE_MAP.put(Collection.class, ArangoResultConverter.class.getMethod("convertList"));
TYPE_MAP.put(Page.class, ArangoResultConverter.class.getMethod("convertPage"));
TYPE_MAP.put(Slice.class, ArangoResultConverter.class.getMethod("convertPage"));
TYPE_MAP.put(Set.class, ArangoResultConverter.class.getMethod("convertSet"));
TYPE_MAP.put(ArangoCursor.class, ArangoResultConverter.class.getMethod("convertArangoCursor"));
TYPE_MAP.put(GeoResult.class, ArangoResultConverter.class.getMethod("convertGeoResult"));
TYPE_MAP.put(GeoResults.class, ArangoResultConverter.class.getMethod("convertGeoResults"));
TYPE_MAP.put(GeoPage.class, ArangoResultConverter.class.getMethod("convertGeoPage"));
TYPE_MAP.put(Optional.class, ArangoResultConverter.class.getMethod("convertOptional"));
TYPE_MAP.put("array", ArangoResultConverter.class.getMethod("convertArray"));
} catch (final NoSuchMethodException e) {
e.printStackTrace();
}
}
/**
* @param accessor
* @param result
* the query result returned by the driver
* @param operations
* instance of arangoTemplate
* @param domainClass
* class type of documents
*/
public ArangoResultConverter(final ArangoParameterAccessor accessor, final ArangoCursor result,
final ArangoOperations operations, final Class domainClass) {
this.accessor = accessor;
this.result = result;
this.operations = operations;
this.domainClass = domainClass;
}
/**
* Called to convert result from ArangoCursor to given type, by invoking the appropriate converter method
*
* @param type
* @return result in desired type
*/
public Object convertResult(final Class type) {
try {
if (type.isArray()) {
return TYPE_MAP.get("array").invoke(this);
}
if (!TYPE_MAP.containsKey(type)) {
return getNext(result);
}
return TYPE_MAP.get(type).invoke(this);
} catch (final Exception e) {
e.printStackTrace();
return null;
}
}
/**
* Creates a Set return type from the given cursor
*
* @param cursor
* query result from driver
* @return Set containing the results
*/
private Set buildSet(final ArangoCursor cursor) {
return StreamSupport.stream(Spliterators.spliteratorUnknownSize(cursor, 0), false).collect(Collectors.toSet());
}
/**
* Build a GeoResult from the given ArangoCursor
*
* @param cursor
* query result from driver
* @return GeoResult object
*/
private GeoResult buildGeoResult(final ArangoCursor cursor) {
GeoResult geoResult = null;
while (cursor.hasNext() && geoResult == null) {
final Object object = cursor.next();
if (!(object instanceof VPackSlice)) {
continue;
}
final VPackSlice slice = (VPackSlice) object;
final VPackSlice distSlice = slice.get("_distance");
final Double distanceInMeters = distSlice.isDouble() ? distSlice.getAsDouble() : null;
if (distanceInMeters == null) {
continue;
}
final Object entity = operations.getConverter().read(domainClass, slice);
final Distance distance = new Distance(distanceInMeters / 1000, Metrics.KILOMETERS);
geoResult = new GeoResult<>(entity, distance);
}
return geoResult;
}
/**
* Construct a GeoResult from the given object
*
* @param object
* object representing one document in the result
* @return GeoResult object
*/
private GeoResult buildGeoResult(final Object object) {
if (object == null || !(object instanceof VPackSlice)) {
return null;
}
final VPackSlice slice = (VPackSlice) object;
final VPackSlice distSlice = slice.get("_distance");
final Double distanceInMeters = distSlice.isDouble() ? distSlice.getAsDouble() : null;
if (distanceInMeters == null) {
return null;
}
final Object entity = operations.getConverter().read(domainClass, slice);
final Distance distance = new Distance(distanceInMeters / 1000, Metrics.KILOMETERS);
return new GeoResult<>(entity, distance);
}
/**
* Build a GeoResults object with the ArangoCursor returned by query execution
*
* @param cursor
* ArangoCursor containing query results
* @return GeoResults object with all results
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
private GeoResults buildGeoResults(final ArangoCursor cursor) {
final List> list = new LinkedList<>();
cursor.forEachRemaining(o -> {
final GeoResult geoResult = buildGeoResult(o);
if (geoResult != null) {
list.add(geoResult);
}
});
return new GeoResults(list);
}
public Optional convertOptional() {
return Optional.ofNullable(getNext(result));
}
public List convertList() {
return result.asListRemaining();
}
public PageImpl convertPage() {
Assert.notNull(result.getStats().getFullCount(), MISSING_FULL_COUNT);
return new PageImpl<>(result.asListRemaining(), accessor.getPageable(), result.getStats().getFullCount());
}
public Set convertSet() {
return buildSet(result);
}
public ArangoCursor convertArangoCursor() {
return result;
}
public GeoResult convertGeoResult() {
return buildGeoResult(result);
}
public GeoResults convertGeoResults() {
return buildGeoResults(result);
}
public GeoPage convertGeoPage() {
Assert.notNull(result.getStats().getFullCount(), MISSING_FULL_COUNT);
return new GeoPage<>(buildGeoResults(result), accessor.getPageable(), result.getStats().getFullCount());
}
public Object convertArray() {
return result.asListRemaining().toArray();
}
private Object getNext(final ArangoCursor cursor) {
return cursor.hasNext() ? cursor.next() : null;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy