alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Glassfish example source code file (ArrayConversion.java)

This example Glassfish source code file (ArrayConversion.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Glassfish tags/keywords

arrayconversion, byte, character, class, class, float, illegalargumentexception, long, object, object, reflection, set, set, t, t, util

The Glassfish ArrayConversion.java source code

/*
 * 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.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.glassfish.admin.amx.util;

import java.lang.reflect.Array;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

/**
Provides:
- methods to convert arrays of primitive types to corresponding arrays of Object types
- conversion to/from Set
 */
public final class ArrayConversion
{
    private ArrayConversion()
    {
        // disallow instantiation
    }

    private static Object[] convert(Object simpleArray)
    {
        if (!ClassUtil.objectIsPrimitiveArray(simpleArray))
        {
            throw new IllegalArgumentException();
        }

        final String className = simpleArray.getClass().getName();

        final Class theClass = ClassUtil.getArrayElementClass(simpleArray.getClass());

        final int numItems = Array.getLength(simpleArray);

        final Class elementClass = ClassUtil.PrimitiveClassToObjectClass(theClass);

        final Object[] result = (Object[]) Array.newInstance(elementClass, numItems);

        for (int i = 0; i < numItems; ++i)
        {
            result[i] = Array.get(simpleArray, i);
        }

        return (result);
    }

    /**
    Convert an an array of primitive types to an array of Objects of non-primitive
    types eg int to Integer.

    @param array	the array to convert
     */
    public static Object[] toAppropriateType(Object array)
    {
        return convert(array);
    }

    public static Boolean[] toBooleans(boolean[] array)
    {
        return ((Boolean[]) convert(array));
    }

    public static Character[] toCharacters(char[] array)
    {
        return ((Character[]) convert(array));
    }

    public static Byte[] toBytes(byte[] array)
    {
        return ((Byte[]) convert(array));
    }

    public static Short[] toShorts(short[] array)
    {
        return ((Short[]) convert(array));
    }

    public static Integer[] toIntegers(int[] array)
    {
        return ((Integer[]) convert(array));
    }

    public static Long[] toLongs(long[] array)
    {
        return ((Long[]) convert(array));
    }

    public static Float[] toFloats(float[] array)
    {
        return ((Float[]) convert(array));
    }

    public static Double[] toDoubles(double[] array)
    {
        return ((Double[]) convert(array));
    }

    /**
    Create an array whose type is elementType[] of specified size.

    @param elementType	the type of each entry of the array
    @param size			the number of elements
     */
    public static Object[] createObjectArrayType(final Class elementType, final int size)
    {
        final Object[] result = (Object[]) Array.newInstance(elementType, size);

        return (result);
    }

    public static Object[] subArray(final Object[] in, int start, int end)
    {
        final int count = 1 + (end - start);
        final Object[] result = (Object[]) Array.newInstance(ClassUtil.getArrayElementClass(in.getClass()), count);

        for (int i = 0; i < count; ++i)
        {
            result[i] = in[i + start];
        }

        return (result);
    }

    public static <T> Set toSet(T[] array)
    {
        Set<T> theSet = null;
        if (array.length == 0)
        {
            theSet = Collections.emptySet();
        }
        else if (array.length == 1)
        {
            theSet = Collections.singleton(array[ 0]);
        }
        else
        {
            theSet = new HashSet<T>();
            for (int i = 0; i < array.length; ++i)
            {
                theSet.add(array[i]);
            }
        }
        return (theSet);
    }

    /*
    Return true if every element of the array has *exactly* the same class.
     */
    public static boolean hasIdenticalElementClasses(final Object[] a)
    {
        boolean isUniform = true;

        if (a.length > 0)
        {
            final Class matchType = a[ 0].getClass();

            for (int i = 1; i < a.length; ++i)
            {
                if (a[i].getClass() != matchType)
                {
                    isUniform = false;
                    break;
                }
            }
        }

        return (isUniform);
    }

    /**
    Specialize the type of the array (if possible).  For example, if the
    array is an Object[] of Integer, return an Integer[] of Integer.

    @param a			the array to specialize
    @return	a specialized array (if possible) otherwise the original array
     */
    public static Object[] specializeArray(final Object[] a)
    {
        Object[] result = a;

        if (hasIdenticalElementClasses(a) &&
            a.length != 0 &&
            a.getClass() == Object[].class)
        {
            result = createObjectArrayType(a[0].getClass(), a.length);

            System.arraycopy(a, 0, result, 0, a.length);
        }

        return (result);
    }

    /**
    Convert a Set to an array. If specialize is true, then provide
    the most specialized type possible via specializeArray()

    @param s			the Set to convert
    @param specialize	decide whether to specialize the type or not
     */
    public static Object[] setToArray(final Set<?> s, boolean specialize)
    {
        Object[] result = setToArray(s);

        if (specialize && result.length != 0)
        {
            result = specializeArray(result);
        }

        return (result);
    }

    /**
    Convert a Set to an Object[].

    @param s			the Set to convert
     */
    public static Object[] setToArray(final Set<?> s)
    {
        final Object[] out = new Object[s.size()];

        setToArray(s, out);

        return (out);
    }

    /**
    Convert a Set to an Object[].

    @param s			the Set to convert
    @param out			the output array, must be of size s.size()
     */
    public static Object[] setToArray(final Set<?> s, Object[] out)
    {
        if (out.length != s.size())
        {
            throw new IllegalArgumentException();
        }

        int i = 0;
        for (final Object o : s)
        {
            out[i] = o;
            ++i;
        }

        return (out);
    }

    public static <T> Set arrayToSet(final T[] names)
    {
        final Set<T> set = new HashSet();

        for (int i = 0; i < names.length; ++i)
        {
            set.add(names[i]);
        }

        return (set);
    }

}

Other Glassfish examples (source code examples)

Here is a short list of links related to this Glassfish ArrayConversion.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.