Serialization.md

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: https://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: https://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: https://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();

manually 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);