Serialization

VelocyPack serialization

Since version 4.1.11 you can extend the VelocyPack serialization by registering additional VPackModules on ArangoDB.Builder.

Java 8 types

GitHub: github.com/arangodb/java-velocypack-module-jdk8

Added support for:

  • java.time.Instant
  • java.time.LocalDate
  • java.time.LocalDateTime
  • java.time.ZonedDateTime
  • java.time.OffsetDateTime
  • java.time.ZoneId
  • java.util.Optional
  • java.util.OptionalDouble
  • java.util.OptionalInt
  • java.util.OptionalLong
<dependencies>
  <dependency>
    <groupId>com.arangodb</groupId>
    <artifactId>velocypack-module-jdk8</artifactId>
    <version>1.1.0</version>
  </dependency>
</dependencies>
ArangoDB arangoDB = new ArangoDB.Builder().registerModule(new VPackJdk8Module()).build();

Scala types

GitHub: github.com/arangodb/java-velocypack-module-scala

Added support for:

  • scala.Option
  • scala.collection.immutable.List
  • scala.collection.immutable.Map
  • scala.math.BigInt
  • scala.math.BigDecimal
<dependencies>
  <dependency>
    <groupId>com.arangodb</groupId>
    <artifactId>velocypack-module-scala</artifactId>
    <version>1.0.2</version>
  </dependency>
</dependencies>
val arangoDB: ArangoDB = new ArangoDB.Builder().registerModule(new VPackScalaModule).build

Joda-Time

GitHub: github.com/arangodb/java-velocypack-module-joda

Added support for:

  • org.joda.time.DateTime
  • org.joda.time.Instant
  • org.joda.time.LocalDate
  • org.joda.time.LocalDateTime
<dependencies>
  <dependency>
    <groupId>com.arangodb</groupId>
    <artifactId>velocypack-module-joda</artifactId>
    <version>1.1.1</version>
  </dependency>
</dependencies>
ArangoDB arangoDB = new ArangoDB.Builder().registerModule(new VPackJodaModule()).build();

Use of jackson as an alternative serializer

Since version 4.5.2, the driver supports alternative serializer to de-/serialize documents, edges and query results. One implementation is VelocyJack which is based on Jackson working with jackson-dataformat-velocypack.

Note: Any registered custom serializer/deserializer or module will be ignored.

custom serialization

ArangoDB arangoDB = new ArangoDB.Builder().registerModule(new VPackModule() {
  @Override
  public <C extends VPackSetupContext<C>> void setup(final C context) {
    context.registerDeserializer(MyObject.class, new VPackDeserializer<MyObject>() {
      @Override
      public MyObject deserialize(VPackSlice parent,VPackSlice vpack,
          VPackDeserializationContext context) throws VPackException {
        MyObject obj = new MyObject();
        obj.setName(vpack.get("name").getAsString());
        return obj;
      }
    });
    context.registerSerializer(MyObject.class, new VPackSerializer<MyObject>() {
      @Override
      public void serialize(VPackBuilder builder,String attribute,MyObject value,
          VPackSerializationContext context) throws VPackException {
        builder.add(attribute, ValueType.OBJECT);
        builder.add("name", value.getName());
        builder.close();
      }
    });
  }
}).build();

JavaBeans

The driver can serialize/deserialize JavaBeans. They need at least a constructor without parameter.

public class MyObject {

  private String name;
  private Gender gender;
  private int age;

  public MyObject() {
    super();
  }

}

Internal fields

To use Arango-internal fields (like _id, _key, _rev, _from, _to) in your JavaBeans, use the annotation DocumentField.

public class MyObject {

  @DocumentField(Type.KEY)
  private String key;

  private String name;
  private Gender gender;
  private int age;

  public MyObject() {
    super();
  }

}

Serialized fieldnames

To use a different serialized name for a field, use the annotation SerializedName.

public class MyObject {

  @SerializedName("title")
  private String name;

  private Gender gender;
  private int age;

  public MyObject() {
    super();
  }

}

Ignore fields

To ignore fields at serialization/deserialization, use the annotation Expose

public class MyObject {

  @Expose
  private String name;
  @Expose(serialize = true, deserialize = false)
  private Gender gender;
  private int age;

  public MyObject() {
    super();
  }

}

Custom serializer

ArangoDB arangoDB = new ArangoDB.Builder().registerModule(new VPackModule() {
  @Override
  public <C extends VPackSetupContext<C>> void setup(final C context) {
    context.registerDeserializer(MyObject.class, new VPackDeserializer<MyObject>() {
      @Override
      public MyObject deserialize(VPackSlice parent,VPackSlice vpack,
          VPackDeserializationContext context) throws VPackException {
        MyObject obj = new MyObject();
        obj.setName(vpack.get("name").getAsString());
        return obj;
      }
    });
    context.registerSerializer(MyObject.class, new VPackSerializer<MyObject>() {
      @Override
      public void serialize(VPackBuilder builder,String attribute,MyObject value,
          VPackSerializationContext context) throws VPackException {
        builder.add(attribute, ValueType.OBJECT);
        builder.add("name", value.getName());
        builder.close();
      }
    });
  }
}).build();

Manual serialization

To de-/serialize from and to VelocyPack before or after a database call, use the ArangoUtil from the method util() in ArangoDB, ArangoDatabase, ArangoCollection, ArangoGraph, ArangoEdgeCollectionor ArangoVertexCollection.

ArangoDB arangoDB = new ArangoDB.Builder();
VPackSlice vpack = arangoDB.util().serialize(myObj);
ArangoDB arangoDB = new ArangoDB.Builder();
MyObject myObj = arangoDB.util().deserialize(vpack, MyObject.class);