Vertex.java

package com.tinkerpop.blueprints;

/**
 * A vertex maintains pointers to both a set of incoming and outgoing edges.
 * The outgoing edges are those edges for which the vertex is the tail.
 * The incoming edges are those edges for which the vertex is the head.
 * Diagrammatically, ---inEdges---> vertex ---outEdges--->.
 *
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 * @author Matthias Brocheler (http://matthiasb.com)
 */
public interface Vertex extends Element {

    /**
     * Return the edges incident to the vertex according to the provided direction and edge labels.
     *
     * @param direction the direction of the edges to retrieve
     * @param labels    the labels of the edges to retrieve
     * @return an iterable of incident edges
     */
    public Iterable<Edge> getEdges(Direction direction, String... labels);

    /**
     * Return the vertices adjacent to the vertex according to the provided direction and edge labels.  This
     * method does not remove duplicate vertices (i.e. those vertices that are connected by more than one edge).
     *
     * @param direction the direction of the edges of the adjacent vertices
     * @param labels    the labels of the edges of the adjacent vertices
     * @return an iterable of adjacent vertices
     */
    public Iterable<Vertex> getVertices(Direction direction, String... labels);

    /**
     * Generate a query object that can be used to fine tune which edges/vertices are retrieved that are incident/adjacent to this vertex.
     *
     * @return a vertex query object with methods for constraining which data is pulled from the underlying graph
     */
    public VertexQuery query();

    /**
     * Add a new outgoing edge from this vertex to the parameter vertex with provided edge label.
     *
     * @param label    the label of the edge
     * @param inVertex the vertex to connect to with an incoming edge
     * @return the newly created edge
     */
    public Edge addEdge(String label, Vertex inVertex);
}