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

Java example source code file (ByteBuffer.java)

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

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytebuffer, capacity, illegal, illegalargumentexception, string

The ByteBuffer.java Java example source code

/*
 * Copyright (c) 2001, 2002, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.corba.se.impl.ior ;


public class ByteBuffer {
    /**
     * The array buffer into which the components of the ByteBuffer are
     * stored. The capacity of the ByteBuffer is the length of this array buffer,
     * and is at least large enough to contain all the ByteBuffer's elements.<p>
     *
     * Any array elements following the last element in the ByteBuffer are 0.
     */
    protected byte elementData[];

    /**
     * The number of valid components in this <tt>ByteBuffer object.
     * Components <tt>elementData[0] through
     * <tt>elementData[elementCount-1] are the actual items.
     *
     * @serial
     */
    protected int elementCount;

    /**
     * The amount by which the capacity of the ByteBuffer is automatically
     * incremented when its size becomes greater than its capacity.  If
     * the capacity increment is less than or equal to zero, the capacity
     * of the ByteBuffer is doubled each time it needs to grow.
     *
     * @serial
     */
    protected int capacityIncrement;

    /**
     * Constructs an empty ByteBuffer with the specified initial capacity and
     * capacity increment.
     *
     * @param   initialCapacity     the initial capacity of the ByteBuffer.
     * @param   capacityIncrement   the amount by which the capacity is
     *                              increased when the ByteBuffer overflows.
     * @exception IllegalArgumentException if the specified initial capacity
     *               is negative
     */
    public ByteBuffer(int initialCapacity, int capacityIncrement) {
        super();
        if (initialCapacity < 0)
            throw new IllegalArgumentException("Illegal Capacity: "+
                                               initialCapacity);
        this.elementData = new byte[initialCapacity];
        this.capacityIncrement = capacityIncrement;
    }

    /**
     * Constructs an empty ByteBuffer with the specified initial capacity and
     * with its capacity increment equal to zero.
     *
     * @param   initialCapacity   the initial capacity of the ByteBuffer.
     * @exception IllegalArgumentException if the specified initial capacity
     *               is negative
     */
    public ByteBuffer(int initialCapacity) {
        this(initialCapacity, 0);
    }

    /**
     * Constructs an empty ByteBuffer so that its internal data array
     * has size <tt>10 and its standard capacity increment is
     * zero.
     */
    public ByteBuffer() {
        this(200);
    }

    /**
     * Trims the capacity of this ByteBuffer to be the ByteBuffer's current
     * size. If the capacity of this cector is larger than its current
     * size, then the capacity is changed to equal the size by replacing
     * its internal data array, kept in the field <tt>elementData,
     * with a smaller one. An application can use this operation to
     * minimize the storage of a ByteBuffer.
     */
    public void trimToSize() {
        int oldCapacity = elementData.length;
        if (elementCount < oldCapacity) {
            byte oldData[] = elementData;
            elementData = new byte[elementCount];
            System.arraycopy(oldData, 0, elementData, 0, elementCount);
        }
    }

    /**
     * This implements the unsynchronized semantics of ensureCapacity.
     * Synchronized methods in this class can internally call this
     * method for ensuring capacity without incurring the cost of an
     * extra synchronization.
     *
     * @see java.util.ByteBuffer#ensureCapacity(int)
     */
    private void ensureCapacityHelper(int minCapacity) {
        int oldCapacity = elementData.length;
        if (minCapacity > oldCapacity) {
            byte oldData[] = elementData;
            int newCapacity = (capacityIncrement > 0) ?
                (oldCapacity + capacityIncrement) : (oldCapacity * 2);
            if (newCapacity < minCapacity) {
                newCapacity = minCapacity;
            }
            elementData = new byte[newCapacity];
            System.arraycopy(oldData, 0, elementData, 0, elementCount);
        }
    }

    /**
     * Returns the current capacity of this ByteBuffer.
     *
     * @return  the current capacity (the length of its internal
     *          data arary, kept in the field <tt>elementData
     *          of this ByteBuffer.
     */
    public int capacity() {
        return elementData.length;
    }

    /**
     * Returns the number of components in this ByteBuffer.
     *
     * @return  the number of components in this ByteBuffer.
     */
    public int size() {
        return elementCount;
    }

    /**
     * Tests if this ByteBuffer has no components.
     *
     * @return  <code>true if and only if this ByteBuffer has
     *          no components, that is, its size is zero;
     *          <code>false otherwise.
     */
    public boolean isEmpty() {
        return elementCount == 0;
    }

    public void append(byte value)
    {
        ensureCapacityHelper(elementCount + 1);
        elementData[elementCount++] = value;
    }

    public void append( int value )
    {
        ensureCapacityHelper(elementCount + 4);
        doAppend( value ) ;
    }

    private void doAppend( int value )
    {
        int current = value ;
        for (int ctr=0; ctr<4; ctr++) {
            elementData[elementCount+ctr] = (byte)(current & 255) ;
            current = current >> 8 ;
        }
        elementCount += 4 ;
    }

    public void append( String value )
    {
        byte[] data = value.getBytes() ;
        ensureCapacityHelper( elementCount + data.length + 4 ) ;
        doAppend( data.length ) ;
        System.arraycopy( data, 0, elementData, elementCount, data.length ) ;
        elementCount += data.length ;
    }

    /**
     * Returns an array containing all of the elements in this ByteBuffer
     * in the correct order.
     *
     * @since 1.2
     */
    public byte[] toArray() {
        return elementData ;
    }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java ByteBuffer.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.