/* * 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); } } }