private static List<LinkedHashMap<String, Object>> getFeaturesForClass(
GraphDatabaseService db, Node classNode) {
List<LinkedHashMap<String, Object>> patternIds = new ArrayList<>();
for (Path p :
db.traversalDescription()
.depthFirst()
.relationships(withName("HAS_CLASS"), Direction.INCOMING)
.evaluator(Evaluators.fromDepth(1))
.evaluator(Evaluators.toDepth(1))
.traverse(classNode)) {
LinkedHashMap<String, Object> featureMap = new LinkedHashMap<>();
if (p.relationships().iterator().hasNext()) {
featureMap.put("frequency", p.relationships().iterator().next().getProperty("matches"));
} else {
featureMap.put("frequency", 0);
}
featureMap.put("feature", ((Long) p.endNode().getId()).intValue());
patternIds.add(featureMap);
}
return patternIds;
}
public static Map<Long, Integer> getTermFrequencyMapForDocument(
GraphDatabaseService db, Long classId) {
Map<Long, Integer> termDocumentMatrix;
String cacheKey = "TERM_DOCUMENT_FREQUENCY_" + classId;
if (vectorSpaceModelCache.getIfPresent(cacheKey) == null) {
Node classNode = db.getNodeById(classId);
termDocumentMatrix = new HashMap<>();
IteratorUtil.asCollection(
db.traversalDescription()
.depthFirst()
.relationships(withName("HAS_CLASS"), Direction.INCOMING)
.evaluator(Evaluators.fromDepth(1))
.evaluator(Evaluators.toDepth(1))
.traverse(classNode))
.stream()
.forEach(
p ->
termDocumentMatrix.put(
p.endNode().getId(), (Integer) p.lastRelationship().getProperty("matches")));
vectorSpaceModelCache.put(cacheKey, termDocumentMatrix);
} else {
termDocumentMatrix = (Map<Long, Integer>) vectorSpaceModelCache.getIfPresent(cacheKey);
}
return termDocumentMatrix;
}
private TraversalDescription friendToSuggestionTraversalDescription() {
return Traversal.description()
.breadthFirst()
.relationships(ConnectionType.KNOWS)
.evaluator(Evaluators.excludeStartPosition())
.evaluator(Evaluators.atDepth(2));
}
public static int getDocumentSizeForFeature(GraphDatabaseService db, Long id) {
int documentSize;
String cacheKey = "DOCUMENT_SIZE_FEATURE_" + id;
if (vectorSpaceModelCache.getIfPresent(cacheKey) == null) {
Node startNode = db.getNodeById(id);
Iterator<Node> classes =
db.traversalDescription()
.depthFirst()
.relationships(withName("HAS_CLASS"), Direction.OUTGOING)
.evaluator(Evaluators.fromDepth(1))
.evaluator(Evaluators.toDepth(1))
.traverse(startNode)
.nodes()
.iterator();
documentSize = IteratorUtil.count(classes);
vectorSpaceModelCache.put(cacheKey, documentSize);
} else {
documentSize = (Integer) vectorSpaceModelCache.getIfPresent(cacheKey);
}
return documentSize;
}
private void checkGeometryNodeIterator() {
TraversalDescription td =
database
.traversalDescription()
.depthFirst()
.relationships(RTreeRelationshipTypes.RTREE_REFERENCE, Direction.OUTGOING)
.evaluator(Evaluators.excludeStartPosition())
.evaluator(Evaluators.toDepth(1));
while ((geometryNodeIterator == null || !geometryNodeIterator.hasNext())
&& allIndexNodeIterator.hasNext()) {
geometryNodeIterator = td.traverse(allIndexNodeIterator.next()).nodes().iterator();
}
}
@SuppressWarnings("deprecation")
@Test
@Transactional
public void testTraverse() throws Exception {
// final TraversalDescription description =
// Traversal.description().relationships(KNOWS).prune(Traversal.pruneAfterDepth(1)).filter(Traversal.returnAllButStartNode());
final TraversalDescription description =
Traversal.description()
.relationships(KNOWS)
.evaluator(Evaluators.toDepth(1))
.evaluator(Evaluators.excludeStartPosition());
assertSingleResult(
"node1",
neo4jTemplate
.traverse(referenceNode, description)
.to(String.class, new PathNodeNameMapper()));
}
public Iterable<Node> getAllIndexInternalNodes() {
TraversalDescription td =
database
.traversalDescription()
.breadthFirst()
.relationships(RTreeRelationshipTypes.RTREE_CHILD, Direction.OUTGOING)
.evaluator(Evaluators.excludeStartPosition());
return td.traverse(getIndexRoot()).nodes();
}
private void canPreFilterNodes(TraversalDescription description) {
Traverser traverser =
description
.uniqueness(Uniqueness.NONE)
.evaluator(Evaluators.atDepth(2))
.traverse(referenceNode());
expectPaths(traverser, "1,2,6", "1,3,5", "1,4,5", "1,5,3", "1,5,4", "1,5,6");
}
private void canPruneTraversalAtSpecificDepth(TraversalDescription description) {
Traverser traverser =
description
.uniqueness(Uniqueness.NONE)
.evaluator(Evaluators.toDepth(1))
.traverse(referenceNode());
expectNodes(traverser, "1", "2", "3", "4", "5");
}
public Iterable<WeightedPath> findAllPaths(Node start, final Node end) {
lastTraverser =
TRAVERSAL
.expand(expander, stateFactory)
.order(new SelectorFactory(costEvaluator))
.evaluator(Evaluators.includeWhereEndNodeIs(end))
.traverse(start);
// Here's how the bidirectional equivalent would look
// lastTraverser = Traversal.bidirectionalTraversal()
// .mirroredSides( TRAVERSAL.expand( expander ).order( new SelectorFactory(
// costEvaluator ) ) )
// .traverse( start, end );
return new Iterable<WeightedPath>() {
public Iterator<WeightedPath> iterator() {
return new StopAfterWeightIterator(lastTraverser.iterator(), costEvaluator);
}
};
}
@Test
public void getAllGroups() throws Exception {
Transaction tx = graphDb.beginTx();
try {
System.out.println("All groups:");
// START SNIPPET: get-groups
Node referenceNode = graphDb.getReferenceNode();
TraversalDescription td =
Traversal.description()
.breadthFirst()
.relationships(RoleRels.ROOT, Direction.INCOMING)
.relationships(RoleRels.PART_OF, Direction.INCOMING)
.evaluator(Evaluators.excludeStartPosition());
for (Node group : td.traverse(referenceNode).nodes()) {
System.out.println(group.getProperty(NAME));
}
// END SNIPPET: get-groups
tx.success();
} finally {
tx.finish();
}
}
public RelationshipFollowingResource(
SecurityContext securityContext, TypedIdResource typedIdResource) {
this.traversalDescription =
Traversal.description()
.depthFirst()
.uniqueness(Uniqueness.NODE_GLOBAL)
.evaluator(Evaluators.excludeStartPosition());
this.visitedRelationships = new LinkedHashSet<AbstractRelationProperty>();
this.securityContext = securityContext;
this.idSet = new LinkedHashSet<Object>();
this.uriParts = new LinkedList<String>();
// add TypedIdResource to list of evaluators
traversalDescription = traversalDescription.evaluator(this);
// store first and last constraint separately
// to be able to access them faster afterwards
firstResource = typedIdResource;
lastResource = typedIdResource;
UuidResource idResource = typedIdResource.getIdResource();
if (idResource instanceof UuidResource) {
logger.log(Level.FINE, "Adding id {0} to id set", idResource.getUriPart());
// add uuid from TypedIdResource to idSet
idSet.add(((UuidResource) idResource).getUriPart());
} else {
logger.log(Level.FINE, "Adding id {0} to id set", idResource.getUriPart());
// add id from TypedIdResource to idSet
idSet.add(idResource.getUuid());
}
}
@Test
public void getJalesMemberships() throws Exception {
Transaction tx = graphDb.beginTx();
try {
System.out.println("Jale's memberships:");
// START SNIPPET: get-user-memberships
Node jale = getUserByName("Jale");
TraversalDescription td =
Traversal.description()
.depthFirst()
.relationships(RoleRels.MEMBER_OF, Direction.OUTGOING)
.relationships(RoleRels.PART_OF, Direction.OUTGOING)
.evaluator(Evaluators.excludeStartPosition());
for (Path path : td.traverse(jale)) {
Node membership = path.endNode();
System.out.println(membership.getProperty(NAME) + " " + (path.length() - 1));
}
// END SNIPPET: get-user-memberships
tx.success();
} finally {
tx.finish();
}
}
@Test
public void getAllAdmins() {
Transaction tx = graphDb.beginTx();
try {
System.out.println("All admins:");
// START SNIPPET: get-admins
Node admins = getGroupByName("Admins");
TraversalDescription td =
Traversal.description()
.breadthFirst()
.relationships(RoleRels.PART_OF, Direction.INCOMING)
.relationships(RoleRels.MEMBER_OF, Direction.INCOMING)
.evaluator(Evaluators.excludeStartPosition());
for (Path path : td.traverse(admins)) {
Node part = path.endNode();
System.out.println(part.getProperty(NAME) + " " + (path.length() - 1));
}
// END SNIPPET: get-admins
tx.success();
} finally {
tx.finish();
}
}
/** @deprecated See {@link org.neo4j.graphdb.traversal.BranchCollisionPolicies#SHORTEST_PATH} */
@Deprecated
public static BranchCollisionDetector shortestPathsCollisionDetector(int maxDepth) {
return new ShortestPathsBranchCollisionDetector(Evaluators.toDepth(maxDepth));
}