Getting error org.neo4j.rest.graphdb.entity.RestNode cannot be cast to java.lang.Iterable

Question

I am trying to filter feeds which contains user actvitity. I am using @QueryResult object to retrieve the result. I need both the feeds and the relationship information of user Liked Feeds. But while retrieving the feeds getting error: org.neo4j.rest.graphdb.entity.RestNode cannot be cast to java.lang.Iterable. (I am using SDN 3.3.0.RELEASE and neo4j 2.1.7)

@QueryResult
public interface FeedsIterableResult {
        @ResultColumn("f")
        Collection<Feed> getFeeds();

        @ResultColumn("r")
        Collection<UserInspiredByFeed> getPaths();
    }

@Query("match (feed:Feed)-[:FEED_CONTAINS_TAG]->(t:Tag)<-[:USER_FAVORITED_TAG]-(u:User{username:{1}}) "
            + "where feed.feedType in {0} "
            + "with u, feed "
            + "optional match (u)-[rel:USER_LIKED_FEED]->(feed) "
            + "return feed as f, rel as r "
            + "union match (u:User{username:{1}})-[:USER_FAVORITED_USER]->(u2:User)-[:USER_LIKED_FEED|:USER_CREATED_FEED]->(feed:Feed) "
            + "where feed.feedType in {0} "
            + "with u2, feed "
            + "optional match (u2)-[rel:USER_LIKED_FEED]->(feed) "
            + "return feed as f, rel as r "         
            + "order by f.timeAdded desc "
            + "skip {2} limit {3}")
FeedsIterableResult getAllFavoriteFeeds(String[] typeFilter, String userName, int skip, int limit);

If I convert the query as suggested by Luanne, I am getting following error: Type mismatch: expected Map, Node or Relationship but was Collection.

New Query:

    @QueryResult
    public interface FeedsIterableResult {
        @ResultColumn("f")
        List<Feed> getFeeds();

        @ResultColumn("r")
        List<UserInspiredByFeed> getPaths();
    }

@Query("match (feed:Feed)-[:FEED_CONTAINS_TAG]->(t:Tag)<-[:USER_FAVORITED_TAG]-(u:User{username:{1}}) "
            + "where feed.feedType in {0} "
            + "with u, feed "
            + "optional match (u)-[rel:USER_INSPIREDBY_FEED]->(feed) "
            + "return collect(feed) as f, collect(rel) as r "
            + "union match (u:User{username:{1}})-[:USER_FAVORITED_USER]->(u2:User)-[:USER_INSPIREDBY_FEED|:USER_CREATED_FEED]->(feed:Feed) "
            + "where feed.feedType in {0} "
            + "with u2, feed "
            + "optional match (u2)-[rel:USER_INSPIREDBY_FEED]->(feed) "
            + "return collect(feed) as f, collect(rel) as r "           
            + "order by f.timeAdded desc "
            + "skip {2} limit {3}")
FeedsIterableResult getAllFavoriteFeeds(String[] typeFilter, String userName, int skip, int limit );

Answer 1

Your query returns feed as f, a node, and rel as r, a relationship. But the FeedsIterableResult expects them to be collections. Each "row" returned by that query will contain a feed node and a rel relationship.

To match your QueryResult, you would have to change your Cypher query to return collections of feeds and rels. Or change FeedsIterableResult to expect single nodes and relationships and have getAllFavoriteFeeds return a Collection of FeedsIterableResult.