/**
* Execute the given update operation of the given triples.
*
* @param conn The connection to execute the update on.
* @param triples The triples to add or delete.
* @param delete Boolean indicating whether the operation is an add or delete.
* @throws ModificationException if the operation fails for any reason.
*/
private void updateTriples(
final Connection conn, final Iterator<Triple> triples, final boolean delete)
throws ModificationException {
Map<PredicateNode, PreparedStatement> statements =
new HashMap<PredicateNode, PreparedStatement>();
try {
while (triples.hasNext()) {
Triple triple = triples.next();
if (LOG.isDebugEnabled()) {
String prefix;
if (delete) {
prefix = "Deleting ";
} else {
prefix = "Adding ";
}
LOG.debug(prefix + triple.toString());
}
PredicateNode predicate = triple.getPredicate();
PreparedStatement statement = statements.get(predicate);
if (statement == null) {
String table = _tableManager.getOrMapTableFor(predicate);
String sql;
if (delete) {
sql = "DELETE FROM " + table + " WHERE s = ? AND o = ?";
} else {
sql = "INSERT INTO " + table + " (s, o) VALUES (?, ?)";
}
statement = conn.prepareStatement(sql);
statements.put(predicate, statement);
}
statement.setString(1, triple.getSubject().toString());
statement.setString(2, triple.getObject().toString());
statement.execute();
}
} catch (SQLException e) {
throw new ModificationException("Database update failed", e);
} finally {
// close all statements we created for this update
Iterator<PreparedStatement> iter = statements.values().iterator();
while (iter.hasNext()) {
PreparedStatement statement = iter.next();
try {
statement.close();
} catch (SQLException e) {
LOG.warn("unable to close statement", e);
}
}
}
}
