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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
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 * file and include the License file at packager/legal/LICENSE.txt.
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 * GPL Classpath Exception:
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package org.glassfish.admin.amx.util;

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

public final class IteratorUtil
{
    private IteratorUtil()
    {
        // disallow instantiation
    }

    public static  Object[] toArray(final Iterator iter)
    {
        final List list = new ArrayList();

        while (iter.hasNext())
        {
            final T elem = iter.next();
            list.add(elem);
        }

        final Object[] result = new Object[list.size()];
        list.toArray(result);

        return (ArrayConversion.specializeArray(result));
    }

    /**
    @param iter
    @return the Class of the elements, or null if all null or different
     */
    public static Class getUniformClass(final Iterator iter)
    {
        Class theClass = null;

        Object next;
        if (iter.hasNext())
        {
            next = iter.next();
            theClass = (next == null) ? null : next.getClass();
        }

        while (iter.hasNext())
        {
            next = iter.next();

            if (next != null && next.getClass() != theClass)
            {
                theClass = null;
                break;
            }
        }

        return (theClass);
    }

    /**
    @param iter
    @param theClass
    @param exactMatch  if true, then subclasses are considered to be different
    @return true if all items are of the same class
     */
    public static  boolean isUniformClass(
            final Iterator iter,
            final Class theClass,
            final boolean exactMatch)
    {
        boolean isUniform = true;

        while (iter.hasNext())
        {
            Object next = iter.next();
            final Class nextClass = (next == null) ? null : next.getClass();

            if (nextClass != theClass && nextClass != null)
            {
                if (exactMatch)
                {
                    isUniform = false;
                    break;
                }

                if (!theClass.isAssignableFrom(nextClass))
                {
                    isUniform = false;
                    break;
                }
            }
        }

        return (isUniform);
    }

}