copy all nodes from one database to another

gistfile1.java

    public void dumpAndLoadTo(String targetPath) throws IOException, InterruptedException {
        // I first tried something like this:
        //     neo4j-shell -path outDir -c "DUMP MATCH n RETURN n;" | neo4j-shell -path targetPath -file -
        // but performance was horrible upon import.
        // See http://stackoverflow.com/questions/28246416/neo4j-export-import-data .

        logger.info("Loading to db " + targetPath);

        GraphDatabaseService dbSrc = getDb();
        GraphDatabaseService dbDest = getDb(targetPath);
        try (Transaction txSource = dbSrc.beginTx(); Transaction txDest = dbDest.beginTx()) {
            Map<Long, Long> nodeIdMap = new HashMap<>();

            for (Node srcNode : GlobalGraphOperations.at(dbSrc).getAllNodes()) {
                Node destNode = dbDest.createNode();
                nodeIdMap.put(srcNode.getId(), destNode.getId());

                for (Label srcLabel : srcNode.getLabels())
                    destNode.addLabel(srcLabel);
                for (String srcKey : srcNode.getPropertyKeys())
                    destNode.setProperty(srcKey, srcNode.getProperty(srcKey));
            }

            for (Relationship srcRel : GlobalGraphOperations.at(dbSrc).getAllRelationships()) {
                Node startNode = dbDest.getNodeById(nodeIdMap.get(srcRel.getStartNode().getId()));
                Node endNode = dbDest.getNodeById(nodeIdMap.get(srcRel.getEndNode().getId()));

                Relationship destRel = startNode.createRelationshipTo(endNode, srcRel.getType());
                for (String srcKey : srcRel.getPropertyKeys())
                    destRel.setProperty(srcKey, srcRel.getProperty(srcKey));
            }

            txSource.success();
            txDest.success();
        }

        dbSrc.shutdown();
        dbDest.shutdown();
    }