| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.openjpa.lib.rop; |
| |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| |
| import org.apache.openjpa.lib.util.Closeable; |
| |
| /** |
| * Iterator wrapped around a {@link ResultObjectProvider}. |
| * |
| * @author Abe White |
| */ |
| public class ResultObjectProviderIterator implements Iterator, Closeable { |
| |
| private final ResultObjectProvider _rop; |
| private Boolean _hasNext = null; |
| private Boolean _open = null; |
| |
| /** |
| * Constructor. Supply object provider. |
| */ |
| public ResultObjectProviderIterator(ResultObjectProvider rop) { |
| _rop = rop; |
| } |
| |
| /** |
| * Close the underlying result object provider. |
| */ |
| @Override |
| public void close() { |
| if (Boolean.TRUE.equals(_open)) { |
| try { |
| _rop.close(); |
| } catch (Exception e) { |
| } |
| _open = Boolean.FALSE; |
| } |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (Boolean.FALSE.equals(_open)) |
| return false; |
| |
| if (_hasNext == null) { |
| try { |
| if (_open == null) { |
| _rop.open(); |
| _open = Boolean.TRUE; |
| } |
| _hasNext = (_rop.next()) ? Boolean.TRUE : Boolean.FALSE; |
| } catch (RuntimeException re) { |
| close(); |
| throw re; |
| } catch (Exception e) { |
| close(); |
| _rop.handleCheckedException(e); |
| return false; |
| } |
| } |
| |
| // close if we reach the end of the list |
| if (!_hasNext.booleanValue()) { |
| close(); |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public Object next() { |
| if (!hasNext()) |
| throw new NoSuchElementException(); |
| try { |
| Object ret = _rop.getResultObject(); |
| _hasNext = null; |
| return ret; |
| } catch (RuntimeException re) { |
| close(); |
| throw re; |
| } catch (Exception e) { |
| close(); |
| _rop.handleCheckedException(e); |
| return null; |
| } |
| } |
| |
| @Override |
| protected void finalize() { |
| close(); |
| } |
| } |