How To Connect To JanusGraph In Java with AnonymousTraversalSource

[ZachMurray]

Problem

How do you connect to to an external JanusGraph-Server with AnonymousTraversalSource?
I'm new to JanusGraph and GraphDBs in-general. I'm using Java-11, TinkerPop3 Gremlin, and Janusgraph:latest.

Repo Steps

1. Download-and-Install Docker
2. Create-and-Startup Cassandra [Docker container] for JanusGraph
   docker run --name jg-cassandra -d -e CASSANDRA_START_RPC=true -p 9160:9160 -p 9042:9042 -p 7199:7199 -p 7001:7001 -p 7000:7000 cassandra:3.11
3. Copy-and-Paste janusgraph.cql.properties into Cassandra [Docker container]
   1. Copy JanusGraph/janusgraph/blob/master/janusgraph-dist/src/assembly/cfilter/conf/janusgraph-cql.properties
   2. docker exec -i jg-cassandra mkdir -p /opt/janusgraph/conf
   3. docker cp janusgraph-cql.properties jq-cassandra:/opt/janusgraph/conf
4. Code-and-Run Test Project
   GraphTraversalSource g = traversal().withRemote("conf/remote-graph.properties");
5. Results
   1. Expected: Program to run
   2. Actual: Program threw up error

Logs

Error

Exception in thread "main" java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException
    at org.apache.tinkerpop.gremlin.process.remote.RemoteConnection.from(RemoteConnection.java:73)
    at org.apache.tinkerpop.gremlin.process.traversal.AnonymousTraversalSource.withRemote(AnonymousTraversalSource.java:76)
    at org.apache.tinkerpop.gremlin.process.traversal.AnonymousTraversalSource.withRemote(AnonymousTraversalSource.java:66)
    at Main.main(Main.java:10)
Caused by: java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
    at org.apache.tinkerpop.gremlin.process.remote.RemoteConnection.from(RemoteConnection.java:71)
    ... 3 more
Caused by: java.lang.IllegalStateException: java.lang.IllegalStateException: Could not establish serializer - org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0
    at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteConnection.<init>(DriverRemoteConnection.java:84)
    ... 9 more
Caused by: java.lang.IllegalStateException: Could not establish serializer - org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0
    at org.apache.tinkerpop.gremlin.driver.Cluster.getBuilderFromSettings(Cluster.java:228)
    at org.apache.tinkerpop.gremlin.driver.Cluster.build(Cluster.java:173)
    at org.apache.tinkerpop.gremlin.driver.Cluster.open(Cluster.java:265)
    at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteConnection.<init>(DriverRemoteConnection.java:80)
    ... 9 more

Process finished with exit code 1

Code

Main.java

import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;

import static org.apache.tinkerpop.gremlin.process.traversal.AnonymousTraversalSource.traversal;

public class Main {
    public static void main(String[] args) throws Exception {
        GraphTraversalSource g = traversal().withRemote("src/main/resources/conf/remote-graph.properties");
    }
}

remote-graph.properties

gremlin.remote.remoteConnectionClass=org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteConnection
gremlin.remote.driver.clusterFile=src/main/resources/conf/remote-objects.yaml
gremlin.remote.driver.sourceName=g

remote-objects.yaml

hosts: [localhost]
port: 8182
serializer: {
  className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0,
  config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }

[hadoopmarc]

Answered on https://stackoverflow.com/questions/76131305/how-to-connect-to-janusgraph-in-java-with-anonymoustraversalsource/76135516#76135516 No problem, it was a confusing situation indeed.

[ZachMurray]

This did fix my issue - Thanks Marc!

    <dependencies>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j2-impl</artifactId>
            <version>2.20.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.tinkerpop</groupId>
            <artifactId>gremlin-core</artifactId>
            <version>3.6.2</version>
        </dependency>
<!--        <dependency>-->
<!--            <groupId>org.janusgraph</groupId>-->
<!--            <artifactId>janusgraph-core</artifactId>-->
<!--            <version>1.0.0-20230424-065649.dcd3240</version>-->
<!--        </dependency>-->
        <!-- https://mvnrepository.com/artifact/org.janusgraph/janusgraph-core -->
        <dependency>
            <groupId>org.janusgraph</groupId>
            <artifactId>janusgraph-core</artifactId>
            <version>0.6.4-20230429-020227.dc3f877</version>
        </dependency>
    </dependencies>