janusgraph源码分析1-下载编译启动

- 源码
- janusgraphcategories:
    - 源码分析

# 编译完整的
mvn -settings ~/opt/soft/apache-maven-3.5.0/conf/settings.xml -Dlicense.skip=true -DskipTests clean install
# 只编译core部分
mvn -pl janusgraph-core -am clean install -Dlicense.skip=true -DskipTests -P prod

-rf :janusgraph-test
mvn -pl janusgraph-test -am clean install -Dlicense.skip=true -DskipTests -P prod

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().has("name", "saturn").next();
        GraphTraversal<Vertex, Map<String, Object>> vertexMapGraphTraversal = g.V(saturn).valueMap();

        GraphTraversal<Vertex, Object> values = g.V(saturn).in("father").in("father").values("name");

        /*
         * The property place is also in a graph index. The property place is an edge property.
         * Therefore, JanusGraph can index edges in a graph index.
         * It is possible to query The Graph of the Gods for all events that have happened within 50 kilometers of Athens
          * (latitude:37.97 and long:23.72).
          * Then, given that information, which vertices were involved in those events.
         */
		System.out.println(g.E().has("place", geoWithin(Geoshape.circle(37.97, 23.72, 50))));
        System.out.println(g.E().has("place", geoWithin(Geoshape.circle(37.97, 23.72, 50)))
                .as("source").inV()
                .as("god2")
                .select("source").outV()
                .as("god1").select("god1", "god2")
                .by("name"));
    }

}

Exception in thread "main" java.lang.IllegalArgumentException: Could not find implementation class: org.janusgraph.diskstorage.berkeleyje.BerkeleyJEStoreManager

        <dependency>
            <groupId>org.janusgraph</groupId>
            <artifactId>janusgraph-berkeleyje</artifactId>
            <version>0.3.0-SNAPSHOT</version>
        </dependency>

Exception in thread "main" java.lang.IllegalArgumentException: Could not find implementation class: org.janusgraph.diskstorage.es.ElasticSearchIndex

Exception in thread "main" org.janusgraph.core.SchemaViolationException: Adding this property for key [~T$SchemaName] and value [rtname] violates a uniqueness constraint [SystemIndex#~T$SchemaName]

This exception is thrown only when you already have added property key to index. So "name" is already added and next time when you run your program somewhere it is again adding "name" property key. So check if that particular code is running twice

11:20:17,051  INFO GraphDatabaseConfiguration:1285 - Set default timestamp provider MICRO
11:20:17,296  INFO GraphDatabaseConfiguration:1492 - Generated unique-instance-id=c0a815a789637-dengzimings-MacBook-Pro-local1
11:20:17,547  INFO Backend:462 - Configuring index [search]
11:20:19,279  INFO Backend:177 - Initiated backend operations thread pool of size 8
11:20:19,461  INFO KCVSLog:753 - Loaded unidentified ReadMarker start time 2018-04-26T03:20:19.408Z into org.janusgraph.diskstorage.log.kcvs.KCVSLog$MessagePuller@73cd37c0
[GraphStep(edge,[]), HasStep([place.geoWithin(BUFFER (POINT (23.72 37.97), 0.44966))])]
[GraphStep(edge,[]), HasStep([place.geoWithin(BUFFER (POINT (23.72 37.97), 0.44966))])@[source], EdgeVertexStep(IN)@[god2], SelectOneStep(last,source), EdgeVertexStep(OUT)@[god1], SelectStep(last,[god1, god2],[value(name)])]
11:20:29,578  INFO ManagementLogger:192 - Received all acknowledgements for eviction [1]

yellow open   janusgraph_edges    QT-E7AV6SMWr8Cu_ywKsXg   5   1          6            0     13.7kb         13.7kb
yellow open   janusgraph_vertices gE4TSXFATnSZUWYdAf46Xg   5   1          6            0     10.9kb         10.9kb

g.E().has("place", geoWithin(Geoshape.circle(37.97, 23.72, 50)))
                .as("source").inV()
                .as("god2")
                .select("source").outV()
                .as("god1").select("god1", "god2")
                .by("name")