Question

我正在尝试访问并将数据保存到我的neo4j服务器，但是尽管我的代码和server-properties.file都显示了相同的数据库位置，但我无法在webadmin界面中看到结果。

这是我写的代码（因为我之前创建过用户，不包括用户创建代码）：

package graph;

import java.util.Iterator;
import java.util.Random;

import org.neo4j.graphdb.Direction;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.RelationshipType;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.graphdb.index.Index;

public class GraphTest {

    static GraphDatabaseService graphDb = new GraphDatabaseFactory().newEmbeddedDatabase( "data/graph.db" );
    static Index<Node> nodeIndex = graphDb.index().forNodes("nodes");

    private static enum RelTypes implements RelationshipType
    {
        CALLED
    }

    public static void addRelationships(){
        int caller;
        int temp=0;
        int callee;
        Random rand = new Random();

        for(int i = 0 ;i<1000;i++){
            caller=rand.nextInt(100);
            temp=rand.nextInt(100);
            while(temp==caller)
                temp=rand.nextInt(100);
            callee=temp;


            String callerName = idToUserName( caller );
            Node foundCaller= nodeIndex.get( "uname", callerName ).getSingle();
            System.out.println( "The username of user " + caller + " is "
            + foundCaller.getProperty( "uname" ) );

            String calleeName = idToUserName( callee);
            Node foundCallee= nodeIndex.get( "uname", calleeName ).getSingle();
            System.out.println( "The username of user " + callee + " is "
            + foundCallee.getProperty( "uname" ) );


            System.out.println(callerName+" called " + calleeName);

            foundCaller.createRelationshipTo(foundCallee, RelTypes.CALLED);
            Iterable<Relationship> rels = foundCaller.getRelationships(RelTypes.CALLED, Direction.OUTGOING);
            Iterator<Relationship> x = rels.iterator();
            while(x.hasNext()){
                Relationship r = x.next();
                System.out.println(r.toString());
            }

        }

    }

    private static String idToUserName( final int id )
    {
        return "user" + String.valueOf(id) ;
    }

    private static Node createAndIndexUser( final String username )
    {
        Node node = graphDb.createNode();
        node.setProperty( "uname", username );
        nodeIndex.add( node,"uname", username );
        return node;
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Node firstNode;
        Node secondNode;
        Relationship relationship;

        System.out.println(nodeIndex.getName()+"  " +
nodeIndex.getGraphDatabase().getNodeById(45).getProperty("uname") );
        registerShutdownHook( graphDb );

        Transaction tx = graphDb.beginTx();
        try
        {
        // Updating operations go here
            // Create some users and index their names with the IndexService

            int idToFind = 67;
            String userName = idToUserName( idToFind );
            Node foundUser = nodeIndex.get( "uname", userName ).getSingle();
            System.out.println( "The username of user " + idToFind + " is "
            + foundUser.getProperty( "uname" ) );


            addRelationships();





            tx.success();

        }
        finally
        {
            tx.finish();

        }

        graphDb.shutdown();

    }

    private static void registerShutdownHook(final GraphDatabaseService graphDb) {
        // TODO Auto-generated method stub
        // Registers a shutdown hook for the Neo4j instance so that it
        // shuts down nicely when the VM exits (even if you "Ctrl-C" the
        // running application).
        Runtime.getRuntime().addShutdownHook( new Thread()
        {
        @Override
        public void run()
        {
        graphDb.shutdown();
        }
        } );

    }

}

这是conf / neo4j-server.properties文件的内容：

# location of the database directory 
org.neo4j.server.database.location=data/graph.db

当我尝试在webadmin界面（http://localhost:7474/webadmin）中编写查询时，例如：

START n=node:nodes(uname="user45")
RETURN n

我收到错误消息：Index 'nodes' doesnt exist那么我怎么能看到它？或者我做错了什么？

Neo4j版本：1.9.3

Answer 1

您真的确定您的代码与Neo4j服务器在同一个工作目录中运行吗？也许你可以在Java程序中打印出当前工作目录的路径？

Answer 2

在Web控制台上，您可以键入index --indexes以查看所有可用索引。

我怎么能在我在java应用程序中创建的Neo4j web admin中看到索引及其节点？

2 个答案: