Using Java to Operate JanusGraph

JanusGraph is a distributed Graph database. You can use Java programming language to operate data through JanusGraph's Java API. Here are the steps to use Java to operate JanusGraph: 1. Add Maven dependency: First, you need to add JanusGraph's Maven dependency in the pom.xml file of the project. Here is a basic dependency example: <dependencies> <dependency> <groupId>org.janusgraph</groupId> <artifactId>janusgraph-core</artifactId> <version>0.5.2</version> </dependency> <dependency> <groupId>org.apache.tinkerpop</groupId> <artifactId>gremlin-core</artifactId> <version>3.4.10</version> </dependency> </dependencies> 2. Connect to JanusGraph: Use Java code to connect to the JanusGraph database. The following is an example of connecting to a local JanusGraph server: import org.janusgraph.core.JanusGraph; import org.janusgraph.core.JanusGraphFactory; public class JanusGraphExample { public static void main(String[] args) { //Connect to JanusGraph JanusGraph janusGraph = JanusGraphFactory.build() .set("storage.backend", "berkeleyje") .set("storage.directory", "/path/to/graph") .open(); //Perform data operations // ... //Close JanusGraph connection janusGraph.close(); } } 3. Data insertion: Use Java code to insert data into JanusGraph. The following is an example of inserting a node and an edge into JanusGraph: import org.apache.tinkerpop.gremlin.structure.Vertex; import org.apache.tinkerpop.gremlin.structure.Edge; import org.apache.tinkerpop.gremlin.structure.Direction; // ... JanusGraph graph = JanusGraphFactory.build() .set("storage.backend", "berkeleyje") .set("storage.directory", "/path/to/graph") .open(); //Create nodes Vertex person = graph.addVertex("person"); person.property("name", "Alice"); person.property("age", 25); //Create nodes Vertex city = graph.addVertex("city"); city.property("name", "London"); //Create edges Edge livesIn = person.addEdge("livesIn", city); livesIn.property("years", 5); graph.tx().commit(); 4. Data Query: Use Java code to query data in JanusGraph. The following is an example of querying the attribute values of a specified node: import org.apache.tinkerpop.gremlin.structure.Vertex; // ... JanusGraph graph = JanusGraphFactory.build() .set("storage.backend", "berkeleyje") .set("storage.directory", "/path/to/graph") .open(); Vertex person = graph.traversal().V().has("name", "Alice").next(); System.out.println(person.property("age").value()); graph.close(); 5. Data modification: Use Java code to modify the data in JanusGraph. The following is an example of modifying the attribute values of a specified node: import org.apache.tinkerpop.gremlin.structure.Vertex; // ... JanusGraph graph = JanusGraphFactory.build() .set("storage.backend", "berkeleyje") .set("storage.directory", "/path/to/graph") .open(); Vertex person = graph.traversal().V().has("name", "Alice").next(); person.property("age", 26); graph.tx().commit(); graph.close(); 6. Data deletion: Use Java code to delete data from JanusGraph. Here is an example of deleting a specified node: import org.apache.tinkerpop.gremlin.structure.Vertex; // ... JanusGraph graph = JanusGraphFactory.build() .set("storage.backend", "berkeleyje") .set("storage.directory", "/path/to/graph") .open(); Vertex person = graph.traversal().V().has("name", "Alice").next(); person.remove(); graph.tx().commit(); graph.close(); The above code example is the basic steps for inserting, modifying, querying, and deleting data using JanusGraph's Java API. According to actual needs, the code can be further improved and adjusted.