Java Iterator to Iterable iterable(final Iterator it)

License

Declaration

public static <A> Iterable<A> iterable(final Iterator<A> it) 

Method Source Code

//package com.java2s;
/*//from   w ww  .jav  a 2s .c  o  m
 * Copyright (C) 2014 Indeed Inc.
 *
 * 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;

public class Main {
    public static <A> Iterable<A> iterable(final Iterator<A> it) {
        return new Iterable<A>() {
            boolean used = false;

            @Override
            public Iterator<A> iterator() {
                if (used)
                    throw new IllegalStateException(
                            "iterator may not be called more than once");
                used = true;
                return it;
            }
        };
    }

    public static <A> Iterable<A> iterable(final Iterator<A> it,
            boolean reusable) {
        if (reusable) {
            ArrayList<A> ret = new ArrayList<A>();
            for (A t : iterable(it)) {
                ret.add(t);
            }
            return ret;
        }
        return iterable(it);
    }
}

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