NullPointerException when executing live query from java client library

[fabianmeyer]

When exeucting a OSQLSynchQuery on a document database, using the java client library, everything works find. When executing the same query string as a OLiveQuery, starting with the "live" keyword (as shown in the documentation http://orientdb.com/docs/2.1/Live-Query.html), a "com.orientechnologies.orient.core.command.OCommandExecutorNotFoundException" will occur.

com.orientechnologies.orient.core.command.OCommandExecutorNotFoundException: Cannot find a command executor for the command request: sql.LIVE SELECT FROM Ontology
    at com.orientechnologies.orient.core.sql.OCommandExecutorSQLDelegate.parse(OCommandExecutorSQLDelegate.java:72)
    at com.orientechnologies.orient.core.sql.OCommandExecutorSQLDelegate.parse(OCommandExecutorSQLDelegate.java:42)
    at com.orientechnologies.orient.core.storage.impl.local.OAbstractPaginatedStorage.command(OAbstractPaginatedStorage.java:1517)
    at com.orientechnologies.orient.core.sql.query.OSQLQuery.run(OSQLQuery.java:72)
    at com.orientechnologies.orient.core.sql.query.OSQLSynchQuery.run(OSQLSynchQuery.java:85)
    at com.orientechnologies.orient.core.query.OQueryAbstract.execute(OQueryAbstract.java:33)
    at com.orientechnologies.orient.server.network.protocol.binary.ONetworkProtocolBinary.command(ONetworkProtocolBinary.java:1323)
    at com.orientechnologies.orient.server.network.protocol.binary.ONetworkProtocolBinary.executeRequest(ONetworkProtocolBinary.java:400)
    at com.orientechnologies.orient.server.network.protocol.binary.OBinaryNetworkProtocolAbstract.execute(OBinaryNetworkProtocolAbstract.java:223)
    at com.orientechnologies.common.thread.OSoftThread.run(OSoftThread.java:77)

When executing the same OLiveQuery without the "live" keyword, a NullPointerException will occur.

com.orientechnologies.orient.core.exception.OStorageException: Error on executing command: sql.SELECT FROM Ontology
    at com.orientechnologies.orient.client.remote.OStorageRemote.handleException(OStorageRemote.java:1768)
    at com.orientechnologies.orient.client.remote.OStorageRemote.command(OStorageRemote.java:1241)
    at com.orientechnologies.orient.client.remote.OStorageRemoteThread.command(OStorageRemoteThread.java:444)
    at com.orientechnologies.orient.core.sql.query.OSQLQuery.run(OSQLQuery.java:72)
    at com.orientechnologies.orient.core.sql.query.OSQLSynchQuery.run(OSQLSynchQuery.java:85)
    at com.orientechnologies.orient.core.query.OQueryAbstract.execute(OQueryAbstract.java:33)
    at com.orientechnologies.orient.core.sql.query.OLiveQuery.execute(OLiveQuery.java:18)
    at com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx.query(ODatabaseDocumentTx.java:719)
    ... 2 more
Caused by: java.lang.NullPointerException
    at com.orientechnologies.orient.client.remote.OStorageRemote.command(OStorageRemote.java:1218)
    ... 8 more

Example code:

        String qwryString = "SELECT FROM Ontology";

        // Simply query - Works just fine
        db.query(new OSQLSynchQuery<>(qwryString)).stream().map(res -> res.toString()).forEach(System.out::println);

        // Live query with 'live' keyword -> OCommandExecutorNotFoundException
        try {
            db.query(new OLiveQuery<>("LIVE " + qwryString, listener));
        } catch (Throwable t) {
            t.printStackTrace();
        }

        // Live query without 'live' keyword -> NullPointerException
        try {
            db.query(new OLiveQuery<>(qwryString, listener));
        } catch (Throwable t) {
            t.printStackTrace();
        }

[luigidellaquila]

Hi @fabianmeyer

Which version are you using? If you are in 2.1.x, did you enable the LiveQuery plugin?

Thanks

Luigi

[fabianmeyer]

Hi, thanks for the fast answer! I'm, in fact, using 2.1.6 and missed the section in the documentation stating that it is disabled by default before 2.2.

Sorry for the inconvinience, it works now!