added VPackJsonSerializer for VPackParser

Author: Mark

ChangeLog

@@ -3,6 +3,7 @@ v4.1.2 (2016-11-xx)
 * fixed GraphEntity for ArangoDatabase.getGraphs() (field name is null)
 * added VelocyPack UTC_DATE parsing to Json String (ISO 8601)
 * added configuration methods for VPackParser in ArangoDB.Builder
+* added VPackJsonSerializer for VPackParser
 
 v4.1.1 (2016-11-09)
 ---------------------------

src/main/java/com/arangodb/ArangoDB.java

@@ -49,6 +49,7 @@
 import com.arangodb.velocypack.VPackDeserializer;
 import com.arangodb.velocypack.VPackInstanceCreator;
 import com.arangodb.velocypack.VPackJsonDeserializer;
+import com.arangodb.velocypack.VPackJsonSerializer;
 import com.arangodb.velocypack.VPackParser;
 import com.arangodb.velocypack.VPackSerializer;
 import com.arangodb.velocypack.ValueType;
@@ -194,6 +195,11 @@ public Builder registerJsonDeserializer(
 			return this;
 		}
 
+		public <T> Builder registerJsonSerializer(final Class<T> clazz, final VPackJsonSerializer<T> serializer) {
+			vpackParser.registerSerializer(clazz, serializer);
+			return this;
+		}
+
 		public ArangoDB build() {
 			return new ArangoDB(
 					new CommunicationSync.Builder().host(host).port(port).timeout(timeout).user(user).password(password)

src/main/java/com/arangodb/velocypack/VPackJsonSerializer.java

@@ -0,0 +1,33 @@
+/*
+ * DISCLAIMER
+ *
+ * Copyright 2016 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.velocypack;
+
+import com.arangodb.velocypack.exception.VPackException;
+
+/**
+ * @author Mark - mark at arangodb.com
+ *
+ */
+public interface VPackJsonSerializer<T> {
+
+	void serialize(VPackBuilder builder, String attribute, T value) throws VPackException;
+
+}

src/main/java/com/arangodb/velocypack/VPackParser.java

@@ -53,11 +53,13 @@ public class VPackParser {
 	private static final String NON_REPRESENTABLE_TYPE = "(non-representable type)";
 	private final Map<ValueType, VPackJsonDeserializer> deserializers;
 	private final Map<String, Map<ValueType, VPackJsonDeserializer>> deserializersByName;
+	private final Map<Class<?>, VPackJsonSerializer<?>> serializers;
 
 	public VPackParser() {
 		super();
 		deserializers = new HashMap<ValueType, VPackJsonDeserializer>();
 		deserializersByName = new HashMap<String, Map<ValueType, VPackJsonDeserializer>>();
+		serializers = new HashMap<Class<?>, VPackJsonSerializer<?>>();
 	}
 
 	public String toJson(final VPackSlice vpack) throws VPackException {
@@ -100,6 +102,11 @@ private VPackJsonDeserializer getDeserializer(final String attribute, final Valu
 		return deserializer;
 	}
 
+	public VPackParser registerSerializer(final Class<?> type, final VPackJsonSerializer<?> serializer) {
+		serializers.put(type, serializer);
+		return this;
+	}
+
 	private void parse(
 		final VPackSlice parent,
 		final String attribute,
@@ -180,7 +187,7 @@ public VPackSlice fromJson(final String json) throws VPackException {
 	public VPackSlice fromJson(final String json, final boolean includeNullValues) throws VPackException {
 		final VPackBuilder builder = new VPackBuilder();
 		final JSONParser parser = new JSONParser();
-		final ContentHandler contentHandler = new VPackContentHandler(builder, includeNullValues);
+		final ContentHandler contentHandler = new VPackContentHandler(builder, includeNullValues, serializers);
 		try {
 			parser.parse(json, contentHandler);
 		} catch (final ParseException e) {
@@ -194,11 +201,14 @@ private static class VPackContentHandler implements ContentHandler {
 		private final VPackBuilder builder;
 		private String attribute;
 		private final boolean includeNullValues;
+		private final Map<Class<?>, VPackJsonSerializer<?>> serializers;
 
-		public VPackContentHandler(final VPackBuilder builder, final boolean includeNullValues) {
+		public VPackContentHandler(final VPackBuilder builder, final boolean includeNullValues,
+			final Map<Class<?>, VPackJsonSerializer<?>> serializers) {
 			this.builder = builder;
 			this.includeNullValues = includeNullValues;
 			attribute = null;
+			this.serializers = serializers;
 		}
 
 		private void add(final ValueType value) throws ParseException {
@@ -297,20 +307,31 @@ public boolean endArray() throws ParseException, IOException {
 			return true;
 		}
 
+		@SuppressWarnings("unchecked")
 		@Override
 		public boolean primitive(final Object value) throws ParseException, IOException {
 			if (value == null) {
 				if (includeNullValues) {
 					add(ValueType.NULL);
 				}
-			} else if (String.class.isAssignableFrom(value.getClass())) {
-				add(String.class.cast(value));
-			} else if (Boolean.class.isAssignableFrom(value.getClass())) {
-				add(Boolean.class.cast(value));
-			} else if (Double.class.isAssignableFrom(value.getClass())) {
-				add(Double.class.cast(value));
-			} else if (Number.class.isAssignableFrom(value.getClass())) {
-				add(Long.class.cast(value));
+			} else {
+				final VPackJsonSerializer<?> serializer = serializers.get(value.getClass());
+				if (serializer != null) {
+					try {
+						((VPackJsonSerializer<Object>) serializer).serialize(builder, attribute, value);
+						attribute = null;
+					} catch (final VPackBuilderException e) {
+						throw new ParseException(ParseException.ERROR_UNEXPECTED_EXCEPTION);
+					}
+				} else if (String.class.isAssignableFrom(value.getClass())) {
+					add(String.class.cast(value));
+				} else if (Boolean.class.isAssignableFrom(value.getClass())) {
+					add(Boolean.class.cast(value));
+				} else if (Double.class.isAssignableFrom(value.getClass())) {
+					add(Double.class.cast(value));
+				} else if (Number.class.isAssignableFrom(value.getClass())) {
+					add(Long.class.cast(value));
+				}
 			}
 			return true;
 		}

src/test/java/com/arangodb/velocypack/VPackParserTest.java

@@ -447,6 +447,20 @@ public void deserialize(
 		assertThat(json, is("{\"a\":\"a1\",\"b\":\"b\"}"));
 	}
 
+	@Test
+	public void customSerializer() throws VPackException {
+		final VPackSlice vpack = new VPackParser().registerSerializer(String.class, new VPackJsonSerializer<String>() {
+			@Override
+			public void serialize(final VPackBuilder builder, final String attribute, final String value)
+					throws VPackException {
+				builder.add(attribute, value + "1");
+			}
+		}).fromJson("{\"a\":\"a\"}");
+		assertThat(vpack.isObject(), is(true));
+		assertThat(vpack.get("a").isString(), is(true));
+		assertThat(vpack.get("a").getAsString(), is("a1"));
+	}
+
 	@Test
 	public void dateToJson() {
 		final VPackSlice vpack = new VPackBuilder().add(new Date(1478766992059L)).slice();