DATAMONGO-1181 - Add Jackson Module for GeoJSON types.

Added GeoJsonModule providing JsonDeserializers for:
  - GeoJsonPoint
  - GeoJsonMultiPoint
  - GeoJsonLineString
  - GeoJsonMultiLineString
  - GeoJsonPolygon
  - GeoJsonMultiPolygon

Author: christophstrobl

spring-data-mongodb/pom.xml

@@ -144,6 +144,13 @@
 			<version>${threetenbp}</version>
 			<optional>true</optional>
 		</dependency>
+		
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>${jackson}</version>
+			<optional>true</optional>
+		</dependency>
 
 		<dependency>
 			<groupId>org.slf4j</groupId>

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/geo/GeoJsonModule.java

@@ -0,0 +1,336 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * 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.mongodb.core.geo;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.springframework.data.geo.GeoModule;
+import org.springframework.data.geo.Point;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+
+/**
+ * @author Christoph Strobl
+ * @since 1.7
+ */
+public class GeoJsonModule extends GeoModule {
+
+	public GeoJsonModule() {
+		super();
+
+		addDeserializer(GeoJsonPoint.class, new GeoJsonPointDeserializer());
+		addDeserializer(GeoJsonMultiPoint.class, new GeoJsonMultiPointDeserializer());
+		addDeserializer(GeoJsonLineString.class, new GeoJsonLineStringDeserializer());
+		addDeserializer(GeoJsonMultiLineString.class, new GeoJsonMultiLineStringDeserializer());
+		addDeserializer(GeoJsonPolygon.class, new GeoJsonPolygonDeserializer());
+		addDeserializer(GeoJsonMultiPolygon.class, new GeoJsonMultiPolygonDeserializer());
+	}
+
+	/**
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static abstract class GeoJsonDeserializer<T extends GeoJson<?>> extends JsonDeserializer<T> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see com.fasterxml.jackson.databind.JsonDeserializer#deserialize(com.fasterxml.jackson.core.JsonParser, com.fasterxml.jackson.databind.DeserializationContext)
+		 */
+		@Override
+		public T deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+
+			JsonNode node = jp.readValueAsTree();
+			JsonNode coordinates = node.get("coordinates");
+
+			if (coordinates != null && coordinates.isArray()) {
+				return doDeserialize((ArrayNode) coordinates);
+			}
+			return null;
+		}
+
+		/**
+		 * Perform the actual deserialization given the {@literal coordinates} as {@link ArrayNode}.
+		 * 
+		 * @param coordinates
+		 * @return
+		 */
+		protected abstract T doDeserialize(ArrayNode coordinates);
+
+		/**
+		 * Get the {@link GeoJsonPoint} representation of given {@link ArrayNode} assuming {@code node.[0]} represents
+		 * {@literal x - coordinate} and {@code node.[1]} is {@literal y}.
+		 * 
+		 * @param node can be {@literal null}.
+		 * @return {@literal null} when given a {@code null} value.
+		 */
+		protected GeoJsonPoint toGeoJsonPoint(ArrayNode node) {
+
+			if (node == null) {
+				return null;
+			}
+
+			return new GeoJsonPoint(node.get(0).asDouble(), node.get(1).asDouble());
+		}
+
+		/**
+		 * Get the {@link Point} representation of given {@link ArrayNode} assuming {@code node.[0]} represents
+		 * {@literal x - coordinate} and {@code node.[1]} is {@literal y}.
+		 * 
+		 * @param node can be {@literal null}.
+		 * @return {@literal null} when given a {@code null} value.
+		 */
+		protected Point toPoint(ArrayNode node) {
+
+			if (node == null) {
+				return null;
+			}
+
+			return new Point(node.get(0).asDouble(), node.get(1).asDouble());
+		}
+
+		/**
+		 * Get the points nested within given {@link ArrayNode}.
+		 * 
+		 * @param node can be {@literal null}.
+		 * @return {@literal empty list} when given a {@code null} value.
+		 */
+		protected List<Point> toPoints(ArrayNode node) {
+
+			if (node == null) {
+				return Collections.emptyList();
+			}
+
+			List<Point> points = new ArrayList<Point>(node.size());
+
+			for (JsonNode coordinatePair : node) {
+				if (coordinatePair.isArray()) {
+					points.add(toPoint((ArrayNode) coordinatePair));
+				}
+			}
+			return points;
+		}
+
+		protected GeoJsonLineString toLineString(ArrayNode node) {
+			return new GeoJsonLineString(toPoints((ArrayNode) node));
+		}
+	}
+
+	/**
+	 * {@link JsonDeserializer} converting GeoJSON representation of {@literal Point}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * { "type": "Point", "coordinates": [10.0, 20.0] }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static class GeoJsonPointDeserializer extends GeoJsonDeserializer<GeoJsonPoint> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.geo.GeoJsonModule.GeoJsonDeserializer#doDeserialize(com.fasterxml.jackson.databind.node.ArrayNode)
+		 */
+		@Override
+		protected GeoJsonPoint doDeserialize(ArrayNode coordinates) {
+			return toGeoJsonPoint(coordinates);
+		}
+	}
+
+	/**
+	 * {@link JsonDeserializer} converting GeoJSON representation of {@literal LineString}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * { 
+	 *   "type": "LineString", 
+	 *   "coordinates": [ 
+	 *     [10.0, 20.0], [30.0, 40.0], [50.0, 60.0]
+	 *   ]
+	 * }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static class GeoJsonLineStringDeserializer extends GeoJsonDeserializer<GeoJsonLineString> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.geo.GeoJsonModule.GeoJsonDeserializer#doDeserialize(com.fasterxml.jackson.databind.node.ArrayNode)
+		 */
+		@Override
+		protected GeoJsonLineString doDeserialize(ArrayNode coordinates) {
+			return new GeoJsonLineString(toPoints(coordinates));
+		}
+	}
+
+	/**
+	 * {@link JsonDeserializer} converting GeoJSON representation of {@literal MultiPoint}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * { 
+	 *   "type": "MultiPoint", 
+	 *   "coordinates": [ 
+	 *     [10.0, 20.0], [30.0, 40.0], [50.0, 60.0]
+	 *   ]
+	 * }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static class GeoJsonMultiPointDeserializer extends GeoJsonDeserializer<GeoJsonMultiPoint> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.geo.GeoJsonModule.GeoJsonDeserializer#doDeserialize(com.fasterxml.jackson.databind.node.ArrayNode)
+		 */
+		@Override
+		protected GeoJsonMultiPoint doDeserialize(ArrayNode coordinates) {
+			return new GeoJsonMultiPoint(toPoints(coordinates));
+		}
+	}
+
+	/**
+	 * {@link JsonDeserializer} converting GeoJSON representation of {@literal MultiLineString}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * { 
+	 *   "type": "MultiLineString", 
+	 *   "coordinates": [
+	 *     [ [10.0, 20.0], [30.0, 40.0] ], 
+	 *     [ [50.0, 60.0] , [70.0, 80.0] ]
+	 *   ]
+	 * }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static class GeoJsonMultiLineStringDeserializer extends GeoJsonDeserializer<GeoJsonMultiLineString> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.geo.GeoJsonModule.GeoJsonDeserializer#doDeserialize(com.fasterxml.jackson.databind.node.ArrayNode)
+		 */
+		@Override
+		protected GeoJsonMultiLineString doDeserialize(ArrayNode coordinates) {
+
+			List<GeoJsonLineString> lines = new ArrayList<GeoJsonLineString>(coordinates.size());
+
+			for (JsonNode lineString : coordinates) {
+
+				if (lineString.isArray()) {
+					lines.add(toLineString((ArrayNode) lineString));
+				}
+			}
+
+			return new GeoJsonMultiLineString(lines);
+		}
+	}
+
+	/**
+	 * {@link JsonDeserializer} converting GeoJSON representation of {@literal Polygon}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * { 
+	 *   "type": "Polygon", 
+	 *   "coordinates": [ 
+	 *     [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ] 
+	 *   ]
+	 * }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static class GeoJsonPolygonDeserializer extends GeoJsonDeserializer<GeoJsonPolygon> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.geo.GeoJsonModule.GeoJsonDeserializer#doDeserialize(com.fasterxml.jackson.databind.node.ArrayNode)
+		 */
+		@Override
+		protected GeoJsonPolygon doDeserialize(ArrayNode coordinates) {
+
+			for (JsonNode ring : coordinates) {
+
+				// currently we do not support holes in polygons.
+				GeoJsonPolygon polygon = new GeoJsonPolygon(toPoints((ArrayNode) ring));
+				return polygon;
+			}
+			return null;
+		}
+	}
+
+	/**
+	 * {@link JsonDeserializer} converting GeoJSON representation of {@literal MultiPolygon}.
+	 * 
+	 * <pre>
+	 * <code>
+	 * { 
+	 *   "type": "MultiPolygon", 
+	 *   "coordinates": [
+	 *     [[[102.0, 2.0], [103.0, 2.0], [103.0, 3.0], [102.0, 3.0], [102.0, 2.0]]],
+	 *     [[[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]],
+	 *     [[100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2]]]
+	 *   ]
+	 * }
+	 * </code>
+	 * </pre>
+	 * 
+	 * @author Christoph Strobl
+	 * @since 1.7
+	 */
+	static class GeoJsonMultiPolygonDeserializer extends GeoJsonDeserializer<GeoJsonMultiPolygon> {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.mongodb.core.geo.GeoJsonModule.GeoJsonDeserializer#doDeserialize(com.fasterxml.jackson.databind.node.ArrayNode)
+		 */
+		@Override
+		protected GeoJsonMultiPolygon doDeserialize(ArrayNode coordinates) {
+
+			List<GeoJsonPolygon> polygones = new ArrayList<GeoJsonPolygon>(coordinates.size());
+
+			for (JsonNode polygon : coordinates) {
+				for (JsonNode ring : (ArrayNode) polygon) {
+					polygones.add(new GeoJsonPolygon(toPoints((ArrayNode) ring)));
+				}
+			}
+
+			return new GeoJsonMultiPolygon(polygones);
+		}
+	}
+}