/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jdbi.v3.core.result;
import static java.util.Objects.requireNonNull;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.NoSuchElementException;
import org.jdbi.v3.core.mapper.RowMapper;
import org.jdbi.v3.core.statement.StatementContext;
class ResultSetResultIterator<T> implements ResultIterator<T> {
private final ResultSet results;
private final RowMapper<T> mapper;
private final StatementContext context;
private volatile boolean alreadyAdvanced = false;
private volatile boolean hasNext = false;
private volatile boolean closed = false;
ResultSetResultIterator(ResultSet results,
RowMapper<T> mapper,
StatementContext context) throws SQLException {
this.results = requireNonNull(results);
this.mapper = mapper.specialize(results, context);
this.context = context;
this.context.addCleanable(results::close);
}
@Override
public void close() {
closed = true;
context.close();
}
@Override
public boolean hasNext() {
if (closed) {
return false;
}
if (alreadyAdvanced) {
return hasNext;
}
hasNext = safeNext();
if (hasNext) {
alreadyAdvanced = true;
} else {
close();
}
return hasNext;
}
@Override
public T next() {
if (closed) {
throw new IllegalStateException("iterator is closed");
}
if (!hasNext()) {
close();
throw new NoSuchElementException("No element to advance to");
}
try {
return mapper.map(results, context);
} catch (SQLException e) {
throw new ResultSetException("Error thrown mapping result set into return type", e, context);
} finally {
alreadyAdvanced = safeNext();
if (!alreadyAdvanced) {
close();
}
}
}
@Override
public StatementContext getContext() {
return context;
}
@Override
public void remove() {
throw new UnsupportedOperationException("Deleting from a result set iterator is not yet supported");
}
private boolean safeNext() {
try {
return results.next();
} catch (SQLException e) {
throw new ResultSetException("Unable to advance result set", e, context);
}
}
}