FaKod/gist:2710656

## gistfile1.java
public class RestTraversalMain {


    /**
     * running neo4j community 1.5.2
     * Matrix Example -> Node 391 is Neo
     * <p/>
     * Throws Exception:
     * <p/>
     * Exception in thread "main" java.lang.NullPointerException
     * at org.neo4j.rest.graphdb.entity.RestEntity.<init>(RestEntity.java:59)
     * at org.neo4j.rest.graphdb.entity.RestRelationship.<init>(RestRelationship.java:44)
     * at org.neo4j.rest.graphdb.traversal.RestPathParser.parseFullPath(RestPathParser.java:87)
     * at org.neo4j.rest.graphdb.traversal.RestPathParser.parse(RestPathParser.java:54)
     * at org.neo4j.rest.graphdb.traversal.RestTraverser.parseToPaths(RestTraverser.java:48)
     * at org.neo4j.rest.graphdb.traversal.RestTraverser.<init>(RestTraverser.java:41)
     * at org.neo4j.rest.graphdb.traversal.RestTraversal.traverse(RestTraversal.java:179)
     * at org.neo4j.rest.graphdb.RestTraversalMain.main(RestTraversalMain.java:66)
     */
    public static void main(String[] args) {

        Object[] rels = {DynamicRelationshipType.withName("KNOWS"), Direction.BOTH,
                DynamicRelationshipType.withName("CODED_BY"), Direction.OUTGOING};

        RestGraphDatabase gd = new RestGraphDatabase("http://localhost:7474/db/data/");

        Node nodeNeo = gd.getNodeById(391);

        RestTraversal rt = getRestTraversal(Traverser.Order.BREADTH_FIRST, rels);

        rt.maxDepth(100);

        rt.filter(Traversal.returnAll());

        TraverserImpl result = new TraverserImpl();
        result.iter = rt.traverse(nodeNeo).iterator();
    }


    private static RestTraversal getRestTraversal(Traverser.Order order, Object... rels) {
        Stack<Object[]> entries = calcRels(rels);

        RestTraversal rt = new RestTraversal();
        switch (order) {
            case BREADTH_FIRST:
                rt.breadthFirst();
                break;
            case DEPTH_FIRST:
                rt.depthFirst();
                break;
        }
        // writing down relations
        while (!entries.isEmpty()) {
            Object[] entry = entries.pop();
            rt.relationships((RelationshipType) entry[0], (Direction) entry[1]);
        }
        return rt;
    }

    private static Stack<Object[]> calcRels(Object... rels) {
        if (rels.length % 2 != 0 || rels.length == 0) {
            throw new IllegalArgumentException();
        }

        Stack<Object[]> entries = new Stack<Object[]>();
        for (int i = 0; i < rels.length; i += 2) {
            Object relType = rels[i];
            if (relType == null) {
                throw new IllegalArgumentException(
                        "Null relationship type at " + i);
            }
            if (!(relType instanceof RelationshipType)) {
                throw new IllegalArgumentException(
                        "Expected RelationshipType at var args pos " + i
                                + ", found " + relType);
            }
            Object direction = rels[i + 1];
            if (direction == null) {
                throw new IllegalArgumentException(
                        "Null direction at " + (i + 1));
            }
            if (!(direction instanceof Direction)) {
                throw new IllegalArgumentException(
                        "Expected Direction at var args pos " + (i + 1)
                                + ", found " + direction);
            }
            entries.push(new Object[]{relType, direction});
        }
        return entries;
    }

    private static class Filter implements Predicate<Path> {
        private final TraverserImpl traverser;
        private final ReturnableEvaluator evaluator;

        Filter(TraverserImpl traverser, ReturnableEvaluator returnableEvaluator) {
            this.traverser = traverser;
            this.evaluator = returnableEvaluator;
        }

        public boolean accept(Path position) {
            return evaluator.isReturnableNode(new PositionImpl(traverser,
                    position));
        }
    }

    private static class TraverserImpl implements org.neo4j.graphdb.Traverser, Iterator<Node> {
        private TraversalPosition currentPos;
        private Path nextPath;
        private Iterator<Path> iter;
        private int count;
        private Filter filter;

        public TraversalPosition currentPosition() {
            return currentPos;
        }

        public Collection<Node> getAllNodes() {
            List<Node> result = new ArrayList<Node>();
            for (Node node : this) {
                result.add(node);
            }
            return result;
        }

        public Iterator<Node> iterator() {
            return this;
        }

        public boolean hasNext() {
            while (iter.hasNext()) {
                Path path = iter.next();
                if (filter == null || filter.accept(path)) {
                    nextPath = path;
                    return true;
                }
            }
            nextPath = null;
            return false;
        }

        public Node next() {
            currentPos = new PositionImpl(this, nextPath);
            count++;
            return currentPos.currentNode();
        }

        public void remove() {
            throw new UnsupportedOperationException();
        }
    }

    private static class PositionImpl implements TraversalPosition {
        private final Path position;
        private final int count;

        PositionImpl(TraverserImpl traverser, Path position) {
            this.position = position;
            this.count = traverser.count;
        }

        public Node currentNode() {
            return position.endNode();
        }

        public int depth() {
            return position.length();
        }

        public boolean isStartNode() {
            return position.length() == 0;
        }

        public boolean notStartNode() {
            return !isStartNode();
        }

        public Relationship lastRelationshipTraversed() {
            return position.lastRelationship();
        }

        public Node previousNode() {
            return position.lastRelationship().getOtherNode(position.endNode());
        }

        public int returnedNodesCount() {
            return count;
        }

    }
}
	public class RestTraversalMain {


	/**
	* running neo4j community 1.5.2
	* Matrix Example -> Node 391 is Neo
	* <p/>
	* Throws Exception:
	* <p/>
	* Exception in thread "main" java.lang.NullPointerException
	* at org.neo4j.rest.graphdb.entity.RestEntity.<init>(RestEntity.java:59)
	* at org.neo4j.rest.graphdb.entity.RestRelationship.<init>(RestRelationship.java:44)
	* at org.neo4j.rest.graphdb.traversal.RestPathParser.parseFullPath(RestPathParser.java:87)
	* at org.neo4j.rest.graphdb.traversal.RestPathParser.parse(RestPathParser.java:54)
	* at org.neo4j.rest.graphdb.traversal.RestTraverser.parseToPaths(RestTraverser.java:48)
	* at org.neo4j.rest.graphdb.traversal.RestTraverser.<init>(RestTraverser.java:41)
	* at org.neo4j.rest.graphdb.traversal.RestTraversal.traverse(RestTraversal.java:179)
	* at org.neo4j.rest.graphdb.RestTraversalMain.main(RestTraversalMain.java:66)
	*/
	public static void main(String[] args) {

	Object[] rels = {DynamicRelationshipType.withName("KNOWS"), Direction.BOTH,
	DynamicRelationshipType.withName("CODED_BY"), Direction.OUTGOING};

	RestGraphDatabase gd = new RestGraphDatabase("http://localhost:7474/db/data/");

	Node nodeNeo = gd.getNodeById(391);

	RestTraversal rt = getRestTraversal(Traverser.Order.BREADTH_FIRST, rels);

	rt.maxDepth(100);

	rt.filter(Traversal.returnAll());

	TraverserImpl result = new TraverserImpl();
	result.iter = rt.traverse(nodeNeo).iterator();
	}


	private static RestTraversal getRestTraversal(Traverser.Order order, Object... rels) {
	Stack<Object[]> entries = calcRels(rels);

	RestTraversal rt = new RestTraversal();
	switch (order) {
	case BREADTH_FIRST:
	rt.breadthFirst();
	break;
	case DEPTH_FIRST:
	rt.depthFirst();
	break;
	}
	// writing down relations
	while (!entries.isEmpty()) {
	Object[] entry = entries.pop();
	rt.relationships((RelationshipType) entry[0], (Direction) entry[1]);
	}
	return rt;
	}

	private static Stack<Object[]> calcRels(Object... rels) {
	if (rels.length % 2 != 0 \|\| rels.length == 0) {
	throw new IllegalArgumentException();
	}

	Stack<Object[]> entries = new Stack<Object[]>();
	for (int i = 0; i < rels.length; i += 2) {
	Object relType = rels[i];
	if (relType == null) {
	throw new IllegalArgumentException(
	"Null relationship type at " + i);
	}
	if (!(relType instanceof RelationshipType)) {
	throw new IllegalArgumentException(
	"Expected RelationshipType at var args pos " + i
	+ ", found " + relType);
	}
	Object direction = rels[i + 1];
	if (direction == null) {
	throw new IllegalArgumentException(
	"Null direction at " + (i + 1));
	}
	if (!(direction instanceof Direction)) {
	throw new IllegalArgumentException(
	"Expected Direction at var args pos " + (i + 1)
	+ ", found " + direction);
	}
	entries.push(new Object[]{relType, direction});
	}
	return entries;
	}

	private static class Filter implements Predicate<Path> {
	private final TraverserImpl traverser;
	private final ReturnableEvaluator evaluator;

	Filter(TraverserImpl traverser, ReturnableEvaluator returnableEvaluator) {
	this.traverser = traverser;
	this.evaluator = returnableEvaluator;
	}

	public boolean accept(Path position) {
	return evaluator.isReturnableNode(new PositionImpl(traverser,
	position));
	}
	}

	private static class TraverserImpl implements org.neo4j.graphdb.Traverser, Iterator<Node> {
	private TraversalPosition currentPos;
	private Path nextPath;
	private Iterator<Path> iter;
	private int count;
	private Filter filter;

	public TraversalPosition currentPosition() {
	return currentPos;
	}

	public Collection<Node> getAllNodes() {
	List<Node> result = new ArrayList<Node>();
	for (Node node : this) {
	result.add(node);
	}
	return result;
	}

	public Iterator<Node> iterator() {
	return this;
	}

	public boolean hasNext() {
	while (iter.hasNext()) {
	Path path = iter.next();
	if (filter == null \|\| filter.accept(path)) {
	nextPath = path;
	return true;
	}
	}
	nextPath = null;
	return false;
	}

	public Node next() {
	currentPos = new PositionImpl(this, nextPath);
	count++;
	return currentPos.currentNode();
	}

	public void remove() {
	throw new UnsupportedOperationException();
	}
	}

	private static class PositionImpl implements TraversalPosition {
	private final Path position;
	private final int count;

	PositionImpl(TraverserImpl traverser, Path position) {
	this.position = position;
	this.count = traverser.count;
	}

	public Node currentNode() {
	return position.endNode();
	}

	public int depth() {
	return position.length();
	}

	public boolean isStartNode() {
	return position.length() == 0;
	}

	public boolean notStartNode() {
	return !isStartNode();
	}

	public Relationship lastRelationshipTraversed() {
	return position.lastRelationship();
	}

	public Node previousNode() {
	return position.lastRelationship().getOtherNode(position.endNode());
	}

	public int returnedNodesCount() {
	return count;
	}

	}
	}