Access neo4j nodes and relationships through java

Question

I have already loaded 50k nodes and established relationships between them through talend. I wrote java code to connect to neo4j and try to execute cypher query. It is connecting to neo4j but showing wrong results. My java code is:

package com.Neo4J;

import org.neo4j.cypher.javacompat.ExecutionEngine;
import org.neo4j.cypher.javacompat.ExecutionResult;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;

public class CaseNeo4J {

private static final String Neo4J_DBPath="/neo4j-community-1.9.2/data/graph.db";
GraphDatabaseService gdb;

public void connect(){

    gdb = new GraphDatabaseFactory().newEmbeddedDatabase(Neo4J_DBPath);
    Transaction transaction = gdb.beginTx();
    ExecutionEngine engine = new ExecutionEngine(gdb);
    ExecutionResult result = engine.execute( "start n=node(*) return n");
    System.out.println(result.dumpToString());
}

public static void main(String[] args) {

    CaseNeo4J neoobj = new CaseNeo4J();
    neoobj.connect();

}
}

outputs as :
+-----------+
| n         |
+-----------+
| Node[0]{} |
+-----------+
1 row

Actully it should show 50000 nodes but it is showing ony 1... Any idea?

It seems to me, the embedded database is actually empty. Probably you did not really connect to the database but create a new one. Is the directory /neo4j-community-1.9.2 the downloaded server package from the Neo4j website? Because then, the data should actually be located in /neo4j-community-1.9.2/data/graph.db. If you look now, there will be the directory /neo4j-community-1.9.2/graph.db because your code created it. But it's seemingly empty. — khituras
Yes.. I have downloaded it from neo4j site itself. Also it is not empty because I have localhost:7474 running which shows 50000 nodes and 100000 relationships. Also I am able to run cypher query on web UI which gives me correct results. — Saurabh Deshpande
Yes, but the path is wrong, isn't it? As long as you are pointing your java code to /neo4j-community-1.9.2you won't see the data you inserted into the sever. — khituras
I tried giving path upto graph.db I am getting the same result — Saurabh Deshpande
Sorry if I'm annoying, but what exact path did you give? only graph.db? The full path should be - as I wrote in my first comment /neo4j-community-1.9.2/data/graph.db. If there is still nothing then, I don't know. Perhaps make sure the server is down when using the Java class. — khituras

sirandy sirandy · Accepted Answer · 2015-06-17T23:34:26

Sorry if my inswer is too obvious but have you tried with: MATCH(n) RETURN n as the query?

Access neo4j nodes and relationships through java

1 Answers