Java Collection How to - Create ArrayList Backed Iterator

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Question

We would like to know how to create ArrayList Backed Iterator.

Answer

// w  ww. j av  a2 s.co  m
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;



 class ArrayListBackedIterator {

  private Iterator iter;

  private ArrayList<Object> data;

  public ArrayListBackedIterator() {
    this(new ArrayList<Object>());
  }

  public ArrayListBackedIterator(ArrayList<Object> data) {
    this.data = data;
    this.iter = this.data.iterator();
  }

  public void add(Object item) {
    this.data.add(item);
  }

  public boolean hasNext() {
    return this.iter.hasNext();
  }

  public Object next() {
    return this.iter.next();
  }

  public void remove() {

  }

  public void reset() {
    this.iter = this.data.iterator();
  }

  public void close() throws IOException {
    this.iter = null;
    this.data = null;
  }
}

/**
 * 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.
 */

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