dictionaryutils.java

OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上

/*
 * Copyright (c) 2003-2004, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.shared.cm;

import java.lang.reflect.Array;
import java.util.Dictionary;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

/**
 * * Some utility methods for objects that implement Dictionary. * *
 * 
 * @author Gatespace AB *
 * @version $Revision: 1.1.1.1 $
 */

public final class DictionaryUtils {

    /**
     * * Copy a dictionary. * * Deep copy where values aren't immutable. I.e.
     * Vector and arrays. * *
     * 
     * @param in
     *            The Dictionary to create a copy of. * *
     * @return A copy of the Dictionary.
     */

    static public Dictionary copyDictionary(Dictionary in) {
        if (in == null) {
            return null;
        }
        Hashtable out = new Hashtable();
        Enumeration keys = in.keys();
        while (keys.hasMoreElements()) {
            Object key = keys.nextElement();
            out.put(key, copyValue(in.get(key)));
        }
        return out;
    }

    /**
     * * Recursive comparison of two dictionaries for equality. * * Equality is
     * defined as (o1 == null && 02 == null) || o1.equals(o2) * *
     * 
     * @param first
     *            The first Dictionary to compare. *
     * @param second
     *            The second Dictionary to compare. * *
     * @return true if both dictonaries are either null or recursively equal.
     */

    static public boolean dictionariesAreEqual(Dictionary first,
            Dictionary second) {
        if (bothAreNull(first, second))
            return true;
        if (onlyOneIsNull(first, second))
            return false;
        if (sizeIsNotEqual(first, second))
            return false;

        boolean result = true;
        Enumeration keys = first.keys();
        while (result && keys.hasMoreElements()) {
            Object key = keys.nextElement();
            Object v1 = first.get(key);
            Object v2 = second.get(key);
            result = valuesAreEqual(v1, v2);
        }
        return result;
    }

    static public boolean dictionariesAreNotEqual(Dictionary first,
            Dictionary second) {
        return !dictionariesAreEqual(first, second);
    }

    static private Object copyValue(Object in) {
        if (in == null) {
            return null;
        }
        if (in.getClass().isArray()) {
            return copyArray(in);
        } else if (in instanceof Vector) {
            return copyVector((Vector) in);
        } else {
            return in;
        }
    }

    static private Vector copyVector(Vector in) {
        if (in == null) {
            return null;
        }
        Vector out = new Vector();
        Enumeration elements = in.elements();
        while (elements.hasMoreElements()) {
            out.addElement(copyValue(elements.nextElement()));
        }
        return out;
    }

    static private Object copyArray(Object in) {
        if (in == null) {
            return null;
        }
        int length = Array.getLength(in);
        Object out = Array
                .newInstance(in.getClass().getComponentType(), length);
        for (int i = 0; i < length; ++i) {
            Array.set(out, i, copyValue(Array.get(in, i)));
        }
        return out;
    }

    static private boolean valuesAreEqual(Object first, Object second) {
        if (bothAreNull(first, second))
            return true;
        if (onlyOneIsNull(first, second))
            return false;
        if (classesAreNotEqual(first, second))
            return false;

        if (first.getClass().isArray()) {
            return arraysAreEqual(first, second);
        } else if (first instanceof Vector) {
            return vectorsAreEqual((Vector) first, (Vector) second);
        } else {
            return first.equals(second);
        }
    }

    static private boolean vectorsAreEqual(Vector first, Vector second) {
        if (bothAreNull(first, second))
            return true;
        if (onlyOneIsNull(first, second))
            return false;
        if (sizeIsNotEqual(first, second))
            return false;
        boolean result = true;
        for (int i = first.size(); result && i < first.size(); ++i) {
            result = valuesAreEqual(first.elementAt(i), second.elementAt(i));
        }
        return result;
    }

    static private boolean arraysAreEqual(Object first, Object second) {
        if (bothAreNull(first, second))
            return true;
        if (onlyOneIsNull(first, second))
            return false;
        if (lengthIsNotEqual(first, second))
            return false;
        int length = Array.getLength(first);
        boolean result = true;
        for (int i = 0; result && i < length; ++i) {
            result = valuesAreEqual(Array.get(first, i), Array.get(second, i));
        }
        return result;
    }

    static private boolean bothAreNull(Object first, Object second) {
        return first == null && second == null;
    }

    static private boolean onlyOneIsNull(Object first, Object second) {
        return !bothAreNull(first, second) && (first == null || second == null);
    }

    static private boolean sizeIsNotEqual(Dictionary first, Dictionary second) {
        return first.size() != second.size();
    }

    static private boolean sizeIsNotEqual(Vector first, Vector second) {
        return first.size() != second.size();
    }

    static private boolean lengthIsNotEqual(Object first, Object second) {
        return Array.getLength(first) != Array.getLength(second);
    }

    static private boolean classesAreNotEqual(Object first, Object second) {
        return !first.getClass().equals(second.getClass());
    }
}