如何使用嵌入式Cassandra将Java与Titan连接起来

Question

I installed titan-cassandra-0.4.4 , and I can run cassandra and gremlin perfectly (The local node).

I want to test an algorithm in Java, so I need to connect Java to titan. My pom is:

    <dependency>
        <groupId>com.thinkaurelius.titan</groupId>
        <artifactId>titan-core</artifactId>
        <version>0.4.4</version>
    </dependency>

My codes are:

    BaseConfiguration baseConfiguration = new BaseConfiguration();
    baseConfiguration.setProperty("storage.backend", "cassandra");
    baseConfiguration.setProperty("storage.hostname", "127.0.0.1");
    baseConfiguration.setProperty("storage.tablename","test");

    TitanGraph titanGraph = TitanFactory.open(baseConfiguration);

In the last line, the error is:

Exception in thread "main" java.lang.NoClassDefFoundError: com/netflix/astyanax/connectionpool/exceptions/ConnectionException
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at com.thinkaurelius.titan.diskstorage.Backend.getStorageManager(Backend.java:202)
at com.thinkaurelius.titan.diskstorage.Backend.<init>(Backend.java:97)
at com.thinkaurelius.titan.graphdb.configuration.GraphDatabaseConfiguration.getBackend(GraphDatabaseConfiguration.java:398)
at com.thinkaurelius.titan.graphdb.database.StandardTitanGraph.<init>(StandardTitanGraph.java:78)
at com.thinkaurelius.titan.core.TitanFactory.open(TitanFactory.java:60)
at Connecting.main(Connecting.java:20)
Caused by: java.lang.ClassNotFoundException: com.netflix.astyanax.connectionpool.exceptions.ConnectionException
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 8 more

I first start the cassandra, then titan gremlin.sh, and run the java code at last. I do not know if I was missing something?

Thanks in advance!

Answer 1

You should include a dependency for titan-casssandra .

    <dependency>
        <groupId>com.thinkaurelius.titan</groupId>
        <artifactId>titan-casssandra</artifactId>
        <version>0.4.4</version>
    </dependency>

Also note if you're just getting started with Titan, version 0.4.4 is far out of date. Titan 1.0 was released in September 2015. You can find more information at http://titandb.io