| /** |
| * 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.codehaus.groovy.util; |
| |
| import java.util.Iterator; |
| import groovy.util.BufferedIterator; |
| |
| /** |
| * An implementation for BufferedIterator wraps Iterator. |
| * |
| * @author Andrew Taylor |
| * @since 2.5.0 |
| */ |
| public class IteratorBufferedIterator<T> implements BufferedIterator<T> { |
| |
| private final Iterator<T> iter; |
| private boolean hasBuffered; |
| private T buffered; |
| |
| public IteratorBufferedIterator(Iterator<T> iter) { |
| this.iter = iter; |
| this.hasBuffered = false; |
| } |
| |
| public boolean hasNext() { |
| return hasBuffered || iter.hasNext(); |
| } |
| |
| public T next() { |
| if (hasBuffered) { |
| T buffered = this.buffered; |
| this.buffered = null; |
| hasBuffered = false; |
| return buffered; |
| } else { |
| return iter.next(); |
| } |
| } |
| |
| public void remove() { |
| if (hasBuffered) { |
| throw new IllegalStateException("Can't remove from " + this + " when an item is buffered."); |
| } else { |
| iter.remove(); |
| } |
| } |
| |
| /** |
| * Return the next element to be returned by next() without consuming it. |
| */ |
| public T head() { |
| if (!hasBuffered) { |
| buffered = iter.next(); |
| hasBuffered = true; |
| } |
| return buffered; |
| } |
| } |