CODEWITHSUNDEEP
javatransactionsneo4j
MightySeal
MightySeal

Reputation: 2315

Neo4j transactions error handling

i'm trying to figure out with transactions (i'm using neo4j 1.8.2), but can't really understand how do i handle errors.

For example i'm creating node:

public Node createNode() {
    Transaction tx = getGraphDb().beginTx();
    try {
        Node node = graphDb.createNode();
        tx.success();
        return node;
    } finally {
        tx.finish();
    }
}

What happens if node is not created and how do i get it? Should i check if node is null?

Upvotes: 0

Views: 1452

Answers (2)

tstorms
tstorms

Reputation: 5001

You could use the following code snippet. The exception in the catch clause will tell you what went wrong.

Transaction tx = graphDb.beginTx();     
Node n = null;
try {
    n = graphDb.createNode();
    tx.success();
} catch (Exception e) {
    tx.failure();
} finally {
    tx.finish();
}

The transaction will be rolled back on tx.finish() when tx.failure() is called.

NOTICE: org.neo4j.graphdb.Transaction.finish() has been deprecated in favour of try-with-resource statements see: http://javadox.com/org.neo4j/neo4j-kernel/2.0.3/deprecated-list.html.

Now proper way would be:

try ( Transaction tx = graphDatabaseService.beginTx() )
 {
           //work here
           tx.success();
 }

Upvotes: 2

Mattias Finné
Mattias Finné

Reputation: 3054

tx.failure() isn't really needed in this case. The absence of tx.success() will roll back the transaction as well. So you can say that it's exception-controlled transaction management.

Upvotes: 1

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