org.apache.tinkerpop.gremlin.structure.io.graphson

Class GraphSONWriter

java.lang.Object

org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONWriter

All Implemented Interfaces:

GraphWriter

public final class GraphSONWriter
extends Object
implements GraphWriter

A @{link GraphWriter} that writes a graph and its elements to a JSON-based representation. This implementation only supports JSON data types and is therefore lossy with respect to data types (e.g. a float will become a double). Further note that serialized Map objects do not support complex types for keys. Edge and Vertex objects are serialized to Map instances. If an Element is used as a key, it is coerced to its identifier. Other complex objects are converted via Object.toString() unless a mapper serializer is supplied.

Author:

Stephen Mallette (http://stephen.genoprime.com)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GraphSONWriter.Builder

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.structure.io.GraphWriter

GraphWriter.WriterBuilder<T extends GraphWriter>

Method Summary

Modifier and Type	Method and Description
static GraphSONWriter.Builder	build()
void	writeEdge(OutputStream outputStream, Edge e) Writes an Edge object to the stream.
void	writeGraph(OutputStream outputStream, Graph g) Writes a Graph to stream in an adjacency list format where vertices are written with edges from both directions.
void	writeObject(OutputStream outputStream, Object object) Writes an arbitrary object to the stream.
void	writeProperty(OutputStream outputStream, Property p) Write a Property object to the stream.
void	writeVertex(OutputStream outputStream, Vertex v) Writes a single Vertex with no edges serialized.
void	writeVertex(OutputStream outputStream, Vertex v, Direction direction) Writes a single Vertex to stream where edges only from the specified direction are written.
void	writeVertexProperty(OutputStream outputStream, VertexProperty vp) Write a VertexProperty object to the stream.
void	writeVertices(OutputStream outputStream, Iterator<Vertex> vertexIterator) Writes a list of vertices without edges.
void	writeVertices(OutputStream outputStream, Iterator<Vertex> vertexIterator, Direction direction) Writes a list of vertices in adjacency list format where vertices are written with edges from both directions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

writeGraph

public void writeGraph(OutputStream outputStream,
                       Graph g)
                throws IOException

Writes a Graph to stream in an adjacency list format where vertices are written with edges from both directions. Under this serialization model, edges are grouped by label.

Specified by:

writeGraph in interface GraphWriter

Parameters:

outputStream - the stream to write to.

g - the graph to write to stream.

Throws:

IOException

writeVertex

public void writeVertex(OutputStream outputStream,
                        Vertex v,
                        Direction direction)
                 throws IOException

Writes a single Vertex to stream where edges only from the specified direction are written. Under this serialization model, edges are grouped by label.

Specified by:

writeVertex in interface GraphWriter

Parameters:

direction - the direction of edges to write or null if no edges are to be written.

outputStream - the stream to write to.

v - the vertex to write.

Throws:

IOException

writeVertex

public void writeVertex(OutputStream outputStream,
                        Vertex v)
                 throws IOException

Writes a single Vertex with no edges serialized.

Specified by:

writeVertex in interface GraphWriter

Parameters:

outputStream - the stream to write to.

v - the vertex to write.

Throws:

IOException

writeVertices

public void writeVertices(OutputStream outputStream,
                          Iterator<Vertex> vertexIterator,
                          Direction direction)
                   throws IOException

Writes a list of vertices in adjacency list format where vertices are written with edges from both directions. Under this serialization model, edges are grouped by label.

Specified by:

writeVertices in interface GraphWriter

Parameters:

outputStream - the stream to write to.

vertexIterator - a traversal that returns a list of vertices.

direction - if direction is null then no edges are written.

Throws:

IOException

writeVertices

public void writeVertices(OutputStream outputStream,
                          Iterator<Vertex> vertexIterator)
                   throws IOException

Writes a list of vertices without edges.

Specified by:

writeVertices in interface GraphWriter

Parameters:

outputStream - the stream to write to.

vertexIterator - a iterator that returns a list of vertices.

Throws:

IOException

writeEdge

public void writeEdge(OutputStream outputStream,
                      Edge e)
               throws IOException

Writes an Edge object to the stream. Note that this format is different from the format of an Edge when serialized with a Vertex as done with writeVertex(OutputStream, Vertex, Direction) or writeVertices(OutputStream, Iterator, Direction) in that the edge label is part of the object and vertex labels are included with their identifiers.

Specified by:

writeEdge in interface GraphWriter

Parameters:

outputStream - the stream to write to.

e - the edge to write.

Throws:

IOException

writeVertexProperty

public void writeVertexProperty(OutputStream outputStream,
                                VertexProperty vp)
                         throws IOException

Write a VertexProperty object to the stream.

Specified by:

writeVertexProperty in interface GraphWriter

Parameters:

outputStream - the stream to write to.

vp - the vertex property to write.

Throws:

IOException

writeProperty

public void writeProperty(OutputStream outputStream,
                          Property p)
                   throws IOException

Write a Property object to the stream.

Specified by:

writeProperty in interface GraphWriter

Parameters:

outputStream - the stream to write to.

p - the property to write.

Throws:

IOException

writeObject

public void writeObject(OutputStream outputStream,
                        Object object)
                 throws IOException

Writes an arbitrary object to the stream. Note that Gremlin Server uses this method when serializing output, thus the format of the GraphSON for a Vertex will be somewhat different from the format supplied when using writeVertex(OutputStream, Vertex, Direction). For example, edges will never be included.

Specified by:

writeObject in interface GraphWriter

Parameters:

outputStream - the stream to write to

object - the object to write which will use the standard serializer set

Throws:

IOException

build

public static GraphSONWriter.Builder build()