在java中的neo4j嵌入式数据库中，我应该如何检查两个节点是否相互关联？

Question

How should I check if two nodes have relationship with each other,in neo4j embedded database in java?

I want the syntax please or a tutorial link,I have seen neo4j website but didn't find it.

Thanks.

Answer 1

Given two nodes "nodeA" and "nodeB",

1. gets all relationships attached to "nodeA",

    rels = nodeA.getRelationships(); 

2. iterate through the collection of relationships "rels", for each relationship "rel", test whether the other end node is nodeB

    rel.getOtherNode(nodeA).equals(nodeB) 

3. if the above expression holds true for one of the relationships, then nodeA and nodeB are connected.

Here is the java API for "Node" and "Relationshiip",

http://api.neo4j.org/current/

Answer 2

private boolean sharedRelationshipExists( Node nodeA, long nodeBId)
{
    Iterator<Relationship> iterator = nodeA.getRelationships().iterator();
    while ( iterator.hasNext() )
    {
        if (iterator.next().getOtherNode( nodeA ).getId() == nodeBId) return true;
    }
    return false;
}

// in another part
boolean sharedRelationshipBetweenAB;
if ( nodeA.getDegree() < nodeB.getDegree() )
{
    sharedRelationshipBetweenAB = sharedRelationshipExists( nodeA, nodeB.getId() );
}
else
{
    sharedRelationshipBetweenAB = sharedRelationshipExists( nodeB, nodeA.getId() );
}

the boolean sharedRelationshipBetweenAB will hold your answer