TinkerGraph

<dependency>
   <groupId>com.tinkerpop.blueprints</groupId>
   <artifactId>blueprints-core</artifactId>
   <version>??</version>
</dependency>

TinkerGraph is a lightweight, POJO based, in-memory property graph that serves as the reference implementation for the property graph model. If you have a small graph that can be loaded and saved using the GraphML reader and writer library, then TinkerGraph can be handy to use. It is also great for use in writing unit tests in place of other implementations that require greater resources. TinkerGraph packaged with the core Blueprints distribution.

// in-memory
Graph graph = new TinkerGraph();

// on graph.shutdown() the graph is serialized to disk with Java serialization
Graph graph = new TinkerGraph("/tmp/tinkergraph"); 

There is a hardcoded representation of the graph diagrammed in Property Graph Model. This is useful as a small, play dataset to get acquainted with the Blueprints API.

Graph graph = TinkerGraphFactory.createTinkerGraph();

Configurable Storage

By default, TinkerGraph uses standard Java serialization for persisting its contents to disk, but there are other more portable options as well using the Blueprints IO functions: GML, GraphML and GraphSON.

Graph graph = new TinkerGraph("/tmp/tinkergraph", TinkerGraph.FileType.GML); 
Graph graph = new TinkerGraph("/tmp/tinkergraph", TinkerGraph.FileType.GRAPHML); 
Graph graph = new TinkerGraph("/tmp/tinkergraph", TinkerGraph.FileType.GRAPHSON); 

// the following is the same as the constructor that simply specifies the directory
Graph graph = new TinkerGraph("/tmp/tinkergraph", TinkerGraph.FileType.JAVA); 

In the case of GML, GraphML and GraphSON, TinkerGraph will write two files to the specified directory. One will contain the data for the graph which will be obviously prefixed with an appropriate .gml, .xml or .json extension depending on the option selected. The other file will be a binary metadata file.

Note that TinkerGraph can store any Java object within its properties, however the storage type chosen will limit the property types that can be persisted on shutdown().

GraphFactory Settings

If using GraphFactory to instantiate a TinkerGraph, the following properties will apply:

key	description
blueprints.graph	com.tinkerpop.blueprints.impls.tg.TinkerGraph
blueprints.tg.directory	When absent the GraphFactory assumes that an in-memory TinkerGraph will be used, otherwise this property should be the directory in which to store the TinkerGraph.
blueprints.tg.file-type	If the blueprints.tg.directory is set then this property specifies the storage type for the data and must match one of the available TinkerGraph.FileType enum: JAVA, GRAPHML, GRAPHSON, or GML. If not specified, this setting defaults to JAVA.

TinkerGraph Feature List

supportsDuplicateEdges: true
supportsSelfLoops: true
supportsSerializableObjectProperty: true
supportsBooleanProperty: true
supportsDoubleProperty: true
supportsFloatProperty: true
supportsIntegerProperty: true
supportsPrimitiveArrayProperty: true
supportsUniformListProperty: true
supportsMixedListProperty: true
supportsLongProperty: true
supportsMapProperty: true
supportsStringProperty: true
ignoresSuppliedIds: false
isPersistent: true
isRDFModel: false
isWrapper: false
supportsIndices: true
supportsVertexIndex: true
supportsEdgeIndex: true
supportsKeyIndices: true
supportsVertexKeyIndex: true
supportsEdgeKeyIndex: true
supportsEdgeIteration: true
supportsVertexIteration: true
supportsTransactions: false
supportsThreadedTransactions: false