janusgraph源码分析2-实例debug

http://www.k6k4.com/blog/show/aaapamn4v1547604938237

一、第一遍调试

还是上次的例子 FirstTest：

public class FirstTest {
   

    public static void main(String[] args) {
   

        /*
         * The example below will open a JanusGraph graph instance and load The Graph of the Gods dataset diagrammed above.
         * JanusGraphFactory provides a set of static open methods,
         * each of which takes a configuration as its argument and returns a graph instance.
         * This tutorial calls one of these open methods on a configuration
         * that uses the BerkeleyDB storage backend and the Elasticsearch index backend,
         * then loads The Graph of the Gods using the helper class GraphOfTheGodsFactory.
         * This section skips over the configuration details, but additional information about storage backends,
         * index backends, and their configuration are available in
         * Part III, “Storage Backends”, Part IV, “Index Backends”, and Chapter 13, Configuration Reference.
         */

        // Loading the Graph of the Gods Into JanusGraph
        JanusGraph graph = JanusGraphFactory
                .open("janusgraph-dist/src/assembly/cfilter/conf/janusgraph-berkeleyje-es.properties");

        GraphOfTheGodsFactory.load(graph);
        GraphTraversalSource g = graph.traversal();

        /*
         * The typical pattern for accessing data in a graph database is to first locate the entry point into the graph
         * using a graph index. That entry point is an element (or set of elements) 
         * — i.e. a vertex or edge. From the entry elements,
         * a Gremlin path description describes how to traverse to other elements in the graph via the explicit graph structure.
         * Given that there is a unique index on name property, the Saturn vertex can be retrieved.
         * The property map (i.e. the key/value pairs of Saturn) can then be examined.
         * As demonstrated, the Saturn vertex has a name of "saturn, " an age of 10000, and a type of "titan."
         * The grandchild of Saturn can be retrieved with a traversal that expresses:
         * "Who is Saturn’s grandchild?" (the inverse of "father" is "child"). The result is Hercules.
         */
        // Global Graph Indices
        Vertex saturn = g.V()