Geospatial queries support (#98)

Author: ulhasrm

README.md

@@ -119,6 +119,11 @@ EndingWith
 Like
 NotLike
 Regex
+Distinct
+IsEmpty
+ExistsBy
+IsWithin
+IsNear
 ```
 
 # Community

checkstyle/checkstyle.xml

@@ -249,7 +249,7 @@
         </module>
         <module name="InnerAssignment"/>
         <module name="ReturnCount">
-            <property name="max" value="8"/>
+            <property name="max" value="9"/>
             <property name="maxForVoid" value="8"/>
         </module>
         <module name="NestedIfDepth">

src/main/java/org/springframework/data/hazelcast/repository/query/GeoPredicate.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2008-2018, Hazelcast, Inc. All Rights Reserved.
+ *
+ * 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.
+ */
+package org.springframework.data.hazelcast.repository.query;
+
+import static com.hazelcast.query.impl.IndexUtils.canonicalizeAttribute;
+
+import java.util.Map;
+
+import org.springframework.data.geo.Distance;
+import org.springframework.data.geo.Metric;
+import org.springframework.data.geo.Metrics;
+import org.springframework.data.geo.Point;
+
+import com.hazelcast.query.Predicate;
+import com.hazelcast.query.impl.Extractable;
+/**
+ * Geo Predicate - Used to calculate near and within queries
+ * <li>Finds all the Points within the given distance range from source Point.
+ * <li>Finds all the Points within given Circle.
+ *
+ * @param <K> key of map entry
+ * @param <V> value of map entry
+ * @author Ulhas R Manekar
+ */
+public class GeoPredicate<K, V>
+        implements Predicate<K, V> {
+
+    private static final double KM_TO_MILES = 0.621371;
+    private static final double KM_TO_NEUTRAL = 0.539957;
+    private static final double R = 6372.8;
+
+    final String attributeName;
+    final Point queryPoint;
+    final Distance distance;
+
+    /**
+     * Constructor accepts the name of the attribute which is of type Point.
+     * Constructs a new geo predicate on the given point
+     * @param attribute    the name of the attribute in a object within Map which is of type Point.
+     * @param point        the source point from where the distance is calculated.
+     * @param distance     the Distance object with value and unit of distance.
+     */
+    public GeoPredicate(String attribute, Point point, Distance distance) {
+        this.attributeName = canonicalizeAttribute(attribute);
+        this.queryPoint = point;
+        this.distance = distance;
+    }
+
+    @Override
+    public boolean apply(Map.Entry<K, V> mapEntry) {
+        Object attributeValue = readAttributeValue(mapEntry);
+        if (attributeValue instanceof Point) {
+            return compareDistance((Point) attributeValue);
+        } else {
+            throw new IllegalArgumentException(String.format("Cannot use %s predicate with attribute other than Point",
+                    getClass().getSimpleName()));
+        }
+    }
+
+    private boolean compareDistance(Point point) {
+        double calculatedDistance = calculateDistance(point.getX(), point.getY(), this.queryPoint.getX(),
+                this.queryPoint.getY(), this.distance.getMetric());
+        return calculatedDistance < this.distance.getValue();
+    }
+
+    /**
+     * This method users Haversine formula to calculate the distance between two points
+     * Formula is explained here - https://www.movable-type.co.uk/scripts/gis-faq-5.1.html
+     * Sample Java code is here - https://rosettacode.org/wiki/Haversine_formula#Java
+     * @param lat1 - Latitude of first point.
+     * @param lng1 - Longitude of first point.
+     * @param lat2 - Latitude of second point.
+     * @param lng2 - Longitude of second point.
+     * @param metric - metric to specify where its KILOMETERS, MILES or NEUTRAL
+     * @return
+     */
+    private double calculateDistance(double lat1, double lng1, double lat2, double lng2, Metric metric) {
+        if ((lat1 == lat2) && (lng1 == lng2)) {
+            return 0;
+        } else {
+            double dLat = Math.toRadians(lat2 - lat1);
+            double dLon = Math.toRadians(lng2 - lng1);
+            double lat1Radians = Math.toRadians(lat1);
+            double lat2Radians = Math.toRadians(lat2);
+
+            double a = Math.pow(Math.sin(dLat / 2), 2)
+                + Math.pow(Math.sin(dLon / 2), 2) * Math.cos(lat1Radians) * Math.cos(lat2Radians);
+            double c = 2 * Math.asin(Math.sqrt(a));
+            double dist = R * c;
+
+            if (Metrics.MILES.equals(metric)) {
+                dist = dist * KM_TO_MILES;
+            } else if (Metrics.NEUTRAL.equals(metric)) {
+                dist = dist * KM_TO_NEUTRAL;
+            }
+
+            return dist;
+        }
+    }
+
+    private Object readAttributeValue(Map.Entry<K, V> entry) {
+        Extractable extractable = (Extractable) entry;
+        return extractable.getAttributeValue(this.attributeName);
+    }
+}

src/main/java/org/springframework/data/hazelcast/repository/query/HazelcastQueryCreator.java

@@ -20,6 +20,10 @@
 import com.hazelcast.query.impl.predicates.PagingPredicateImpl;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.domain.Sort;
+import org.springframework.data.geo.Circle;
+import org.springframework.data.geo.Distance;
+import org.springframework.data.geo.Metrics;
+import org.springframework.data.geo.Point;
 import org.springframework.data.keyvalue.core.query.KeyValueQuery;
 import org.springframework.data.mapping.PropertyPath;
 import org.springframework.data.repository.query.ParameterAccessor;
@@ -179,10 +183,11 @@ public HazelcastQueryCreator(PartTree tree, ParameterAccessor parameters) {
             case IS_EMPTY:
             case IS_NOT_EMPTY:
                 return fromEmptyVariant(type, property);
-            /* case EXISTS:
-             * case NEAR:
-             * case WITHIN:
-             */
+            /* case EXISTS:*/
+            case NEAR:
+            case WITHIN:
+                return fromGeoVariant(type, property, iterator);
+
             default:
                 throw new InvalidDataAccessApiUsageException(String.format("Unsupported type '%s'", type));
         }
@@ -329,4 +334,43 @@ private Comparable<?>[] collectToArray(Type type, Iterator<Comparable<?>> iterat
                 throw new InvalidDataAccessApiUsageException(String.format("Logic error for '%s' in query", type));
         }
     }
+
+    private Predicate<?, ?> fromGeoVariant(Type type, String property, Iterator<Comparable<?>> iterator) {
+        final Object item = iterator.next();
+        Point point;
+        Distance distance;
+        if (item instanceof Point) {
+            point = (Point) item;
+            if (!iterator.hasNext()) {
+                throw new InvalidDataAccessApiUsageException(
+                        "Expected to find distance value for geo query. Are you missing a parameter?");
+            }
+
+            Object distObject = iterator.next();
+            if (distObject instanceof Distance) {
+                distance = (Distance) distObject;
+            } else if (distObject instanceof Number) {
+                distance = new Distance(((Number) distObject).doubleValue(), Metrics.KILOMETERS);
+            } else {
+                throw new InvalidDataAccessApiUsageException(String
+                        .format("Expected to find Distance or Numeric value for geo query but was %s.",
+                                distObject.getClass()));
+            }
+        } else if (item instanceof Circle) {
+            point = ((Circle) item).getCenter();
+            distance = ((Circle) item).getRadius();
+        } else {
+            throw new InvalidDataAccessApiUsageException(
+                    String.format("Expected to find a Circle or Point/Distance for geo query but was %s.", item.getClass()));
+        }
+
+        switch (type) {
+            case WITHIN:
+            case NEAR:
+                return new GeoPredicate<>(property, point, distance);
+
+            default:
+                throw new InvalidDataAccessApiUsageException(String.format("Logic error for '%s' in query", type));
+        }
+    }
 }

src/test/java/org/springframework/data/hazelcast/repository/PagingSortingIT.java

@@ -23,7 +23,7 @@
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.test.context.ActiveProfiles;
-import test.utils.Oscars;
+import test.utils.TestData;
 import test.utils.TestConstants;
 import test.utils.TestDataHelper;
 import test.utils.domain.Person;
@@ -73,7 +73,7 @@ public void unpaged() {
         assertThat("First page count matches content", page.getNumberOfElements(), equalTo(content.size()));
         assertThat("First page has all content", (long) page.getNumberOfElements(), equalTo(page.getTotalElements()));
         assertThat("First page has no upper limit", page.getSize(), equalTo(0));
-        assertThat("First page has correct content count", page.getNumberOfElements(), equalTo(Oscars.bestActors.length));
+        assertThat("First page has correct content count", page.getNumberOfElements(), equalTo(TestData.bestActors.length));
         assertThat("First page is only page", page.getTotalPages(), equalTo(1));
     }
 
@@ -136,7 +136,7 @@ public void unsorted() {
             iterator.next();
         }
 
-        assertThat("Correct number, order undefined", count, equalTo(Oscars.bestActors.length));
+        assertThat("Correct number, order undefined", count, equalTo(TestData.bestActors.length));
     }
 
     @Test
@@ -162,7 +162,7 @@ public void sorting() {
             count++;
             previousFirstname = person.getFirstname();
         }
-        assertThat("Everything found ascending", count, equalTo(Oscars.bestActors.length));
+        assertThat("Everything found ascending", count, equalTo(TestData.bestActors.length));
 
         assertThat("1956 winner, last firstname ascending", previousFirstname, equalTo("Yul"));