[MARMOTTA-393] ClassCastException when loading Literal thats stored as a URI

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.1-incubating
• Fix Version/s: 3.2.0, 3.3.0
• Component/s: KiWi Triple Store
• Assignee: Sebastian Schaffert
• Reporter: Alan
• Created: 29/Nov/13 03:29
• Updated: 19/May/14 14:18
• Resolved: 12/Dec/13 12:55

Description

When loading a literal value that already exists as a URI the KiWiConnection.loadLiteral throws an ClassCastException as the returned node is a URI.

Caused by: java.lang.ClassCastException: org.apache.marmotta.kiwi.model.rdf.KiWiUriResource cannot be cast to org.apache.marmotta.kiwi.model.rdf.KiWiLiteral
	at org.apache.marmotta.kiwi.persistence.KiWiConnection.loadLiteral(KiWiConnection.java:627)
	at org.apache.marmotta.kiwi.sail.KiWiValueFactory.createLiteral(KiWiValueFactory.java:435)
	at org.apache.marmotta.kiwi.sail.KiWiValueFactory.createLiteral(KiWiValueFactory.java:350)
	at org.openrdf.rio.helpers.RDFParserHelper.createLiteral(RDFParserHelper.java:250)

Perhaps KiWiConnection.loadLiteral(String value, String lang, KiWiUriResource ltype) could validate the type and return null e.g.

From this:

return (KiWiLiteral)constructNodeFromDatabase(result);

To this:

KiWiNode node = constructNodeFromDatabase(result);
KiWiNode kiWiNode = constructNodeFromDatabase(result);
if(kiWiNode.isLiteral()) {
    return (KiWiLiteral)kiWiNode;
} else {
    return null;
}