Parameter Type Conflict

[NitinJain]

Hello,
I have java function which when used executes a stored procedure which inturn returns a VARCHAR value.

The java function:

public String getDocumentName () {
try {
System.out.println("DBDocument getDocumentName() ID : " +super.getId());
System.out.println(" "
CallableStatement statement = con.prepareCall("{ ? = call getDocumentName (?)}"
statement.registerOutParameter(1,java.sql.Types.VARCHAR);
statement.setLong (1, super.getId());
ResultSet resultSet = statement.executeQuery();
if (!resultSet.next()) {
throw new DBDOMSpException ("SQL Statement"
}
System.out.println("DBDocument getDocumentName() resultSet : "
System.out.println(" "
String result = statement.getString (1);
System.out.println("DBDocument getDocumentName() result : " +result);
System.out.println(" "
resultSet.close();
return result;
} catch (SQLException sqle) {
throw dbDomImplementation.getSqlOrDomException(sqle);
}
}

The stored procedure:

CREATE OR REPLACE FUNCTION getDocumentName (docId NUMBER) RETURN VARCHAR IS

nodeIsDoc BOOLEAN;
result VARCHAR (255);

BEGIN

nodeIsDoc := nodeTypeMatches (docId, 9);

IF NOT nodeIsDoc THEN

DOMException(15);

ELSIF nodeIsDoc IS NULL THEN

raise_application_error (-20205, ' Document does not exists');

ELSE

SELECT name
INTO result
FROM t_Document
WHERE id = docId;

END IF;

RETURN result;

END getDocumentName;

I have checked the value returned by the stored procedure explixitly which looks like this "/home/s0199941/Project/node_in_dtd3.xml".

But the exception of parameter type conflict is thrown.
Can any one suggest something?

Regards