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，但我在 webadmin 界面中看不到结果。
这是我写的代码（因为我之前创建了用户，所以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 (at 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那我怎么能看到它？或者我做错了什么？
Neo4j 版本：1.9.3