GraphTraversal<Vertex, Map<String, Object>> tsList = traversalSource.V().has("request","id_key",114).valueMap();
while(tsList.hasNext())
{
System.out.println(tsList.next().get("status")); //prints result
System.out.println(tsList.next().get("tree_id_key")); //prints result
System.out.println(tsList.next().get("username")); //here throws Exception for any vertex.
System.out.println(tsList.next().get("tree_status"));
}
when I run the above query, I am getting values for any first and second propertyKey. but after getting answers for two Keys It throws NoFastSuchElementException for any propertyKey...Kindly help me..how can I resolve this?
but using below query I am able to get the answer:
GraphTraversal<Vertex, Map<String, Object>> tsList = traversalSource.V().has("request","id_key",114).values("status","tree_id_key","username","tree_status");
while(tsList.hasNext())
{
System.out.println(tsList.next());//prints "status" value
System.out.println(tsList.next());//prints "tree_id_key" value
System.out.println(tsList.next());//prints "username" value
System.out.println(tsList.next());//prints "tree_status" value
}
updated:
GraphTraversal<Vertex, Map<String, Object>> ts = traversalSource.V().has("request","id_key",113).valueMap();
while(ts.hasNext())
{
Map<String, Object> tsList=ts.next();
SuiteIdKey=(long)((ArrayList)tsList.get("suiteKey")).get(0);
seqe=(int)((ArrayList)tsList.get("sequence")).get(0);
}
In the above query, ts will return many rows and for each row I will get suiteIdkey,seqe..I am able to get the answer. But tsList is Map<>, it is not directly returning answer when I use like this =(long)tsList.get("suiteKey"), without ArrayList. Is it the correct way? Kindly help me.
You are asking for two different things in those two traversals. The first one with valueMap() asks that the vertex be converted to a Map, so you don't want to keep calling next() in that loop. Just do:
Map<String, List<Object>> m = traversalSource.V().has("request", "id_key", 114).
valueMap().next();
System.out.println(m.get("status").get(0));
System.out.println(m.get("tree_id_key").get(0));
System.out.println(m.get("username").get(0));
System.out.println(m.get("tree_status").get(0));
Keep in mind above that i'm assuming your traversal always returns one vertex...account for that otherwise if that is not true.
In your second traversal where you do values() you are asking Gremlin to convert grab the values of those specific properties on that vertex and stream them out and thus you need to iterate with multiple calls to next.
Note that typically returning the entire vertex object isn't a recommended practice. It is somewhat akin to SELECT * FROM table in SQL. It is better to get only the fields that you want to get which then gets rid of the ugly multi-property issue of Map<String, List<Object>>:
Map<String, Object> m = traversalSource.V().has("request", "id_key", 114).
project('s`,'tik', 'u', 'ts').
by('status').
by('tree_id_key').
by('username')
by('tree_status').
next();
System.out.println(m.get("s"));
System.out.println(m.get("tik"));
System.out.println(m.get("u"));
System.out.println(m.get("ts"));