graphdb/src/main/java/com/orientechnologies/orient/graph/graphml/OGraphSONUtility.java
public Vertex vertexFromJson(final InputStream json) throws IOException {
    final JsonParser jp = jsonFactory.createParser(json);
    final JsonNode node = jp.readValueAsTree();
    return this.vertexFromJson(node);
  }
public Vertex vertexFromJson(final InputStream json) throws IOException {
    final JsonParser jp = jsonFactory.createParser(json);
    final JsonNode node = jp.readValueAsTree();
    return this.vertexFromJson(node);
  }
Creates a vertex from GraphSON using settings supplied in the constructor.