CODEWITHSUNDEEP
javaneo4jcypher
MarryS
MarryS

Reputation: 175

Neo4J - Java: Result incomplete

I have a strange problem when I'm trying execute a cypher query in an java application. The result.dumpToString()- method shows me the correct result. But when I'm trying to iterate, the last node is always missing (for every executed query):

for (Map<String, Object> row : result) {    
    System.out.println(((Node) row.get("A")));
    System.out.println(((Node) row.get("A")).getProperty("name").toString());           
}

The first output is correct. I see all nodes of the result. In the second output one node is missing, although I know, that the node has a "name"-property.

Has someone an idea? Thank you

Upvotes: 1

Views: 116

Answers (2)

MarryS
MarryS

Reputation: 175

Solved my problem: I was executing the query without beginning a Transaction. Now it works. Nevertheless this is a strange behaviour.

Thank you all

Upvotes: 0

FrobberOfBits
FrobberOfBits

Reputation: 18022

If you're missing a second output, it's likely that the value of that property is a string that is blank. This line:

System.out.println(((Node) row.get("A")).getProperty("name").toString());

In the presence of an attribute "name" that is blank, this will print nothing at all (but a linefeed).

Also, the way you're doing this is a bit dangerous; keep in mind that in general nodes can be missing, so getProperty("name") can return null. Meaning that when you call toString() on it, you can end up with a NullPointerException. It's better to maybe write either this:

row.get("A").getProperty("name", "missing").toString();

That will return "missing" if the property is missing, or:

Object propValue = row.get("A").getProperty("name");
if(propValue != null) 
    System.out.println(propValue.toString());
else System.out.println("Missing name property");

Upvotes: 2

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