Java Iterator to List toList(Iterator iterator)

Description

Gets a list based on an iterator.

License

Apache License

Parameter

Parameter	Description
iterator	the iterator to use, not null

Exception

Parameter	Description
NullPointerException	if iterator parameter is null

Return

a list of the iterator contents

Declaration

public static List toList(Iterator iterator) 

Method Source Code

//package com.java2s;
/*//from www . j  a  v  a  2  s. c  o  m
 *  Copyright 2002-2004 The Apache Software Foundation
 *
 *  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.
 */

import java.util.ArrayList;

import java.util.Iterator;
import java.util.List;

public class Main {
    /**
     * Gets a list based on an iterator.
     * <p>
     * As the wrapped Iterator is traversed, an ArrayList of its values is
     * created. At the end, the list is returned.
     *
     * @param iterator  the iterator to use, not null
     * @return a list of the iterator contents
     * @throws NullPointerException if iterator parameter is null
     */
    public static List toList(Iterator iterator) {
        return toList(iterator, 10);
    }

    /**
     * Gets a list based on an iterator.
     * <p>
     * As the wrapped Iterator is traversed, an ArrayList of its values is
     * created. At the end, the list is returned.
     *
     * @param iterator  the iterator to use, not null
     * @param estimatedSize  the initial size of the ArrayList
     * @return a list of the iterator contents
     * @throws NullPointerException if iterator parameter is null
     * @throws IllegalArgumentException if the size is less than 1
     */
    public static List toList(Iterator iterator, int estimatedSize) {
        if (iterator == null) {
            throw new NullPointerException("Iterator must not be null");
        }
        if (estimatedSize < 1) {
            throw new IllegalArgumentException("Estimated size must be greater than 0");
        }
        List list = new ArrayList(estimatedSize);
        while (iterator.hasNext()) {
            list.add(iterator.next());
        }
        return list;
    }
}

Related

1. toList(Iterator iterator)
2. toList(Iterator src)
3. toList(Iterator iterator)
4. toList(Iterator it)