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

HSQLDB example source code file (HashSet.java)

This example HSQLDB source code file (HashSet.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 - HSQLDB tags/keywords

basehashiterator, basehashmap, hashset, hashset, illegalargumentexception, illegalargumentexception, iterator, iterator, object, object, set, string, stringbuffer

The HSQLDB HashSet.java source code

/* Copyright (c) 2001-2008, The HSQL Development Group
 * 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 HSQL Development Group 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 HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * 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.hsqldb.lib;

import org.hsqldb.store.BaseHashMap;

/**
 * This class does not store null keys.
 *
 * @author fredt@users
 * @version 1.7.2
 * @since 1.7.2
 */
public class HashSet extends BaseHashMap implements Set {

    public HashSet() {
        this(16, 0.75f);
    }

    public HashSet(int initialCapacity) throws IllegalArgumentException {
        this(initialCapacity, 0.75f);
    }

    public HashSet(int initialCapacity,
                   float loadFactor) throws IllegalArgumentException {
        super(initialCapacity, loadFactor, BaseHashMap.objectKeyOrValue,
              BaseHashMap.noKeyOrValue, false);
    }

    public boolean contains(Object key) {
        return super.containsKey(key);
    }

    public Object get(Object key) {

        int lookup = getLookup(key, key.hashCode());

        if (lookup < 0) {
            return null;
        } else {
            return objectKeyTable[lookup];
        }
    }

    public boolean add(Object key) {

        int oldSize = size();

        super.addOrRemove(0, 0, key, null, false);

        return oldSize != size();
    }

    public boolean addAll(Collection c) {

        int      oldSize = size();
        Iterator it      = c.iterator();

        while (it.hasNext()) {
            add(it.next());
        }

        return oldSize != size();
    }

    public boolean addAll(Object[] keys) {

        boolean changed = false;

        for (int i = 0; i < keys.length; i++) {
            if (add(keys[i])) {
                changed = true;
            }
        }

        return changed;
    }

    public boolean remove(Object key) {

        int oldSize = size();

        super.removeObject(key);

        return oldSize != size();
    }

    public Object[] toArray(Object[] a) {

        if (a == null || a.length < size()) {
            a = new Object[size()];
        }

        Iterator it = iterator();

        for (int i = 0; it.hasNext(); i++) {
            a[i] = it.next();
        }

        return a;
    }

    public Iterator iterator() {
        return new BaseHashIterator(true);
    }

    /**
     * Returns a String like "[Drei, zwei, Eins]", exactly like
     * java.util.HashSet.
     */
    public String toString() {

        Iterator     it = iterator();
        StringBuffer sb = new StringBuffer();

        while (it.hasNext()) {
            if (sb.length() > 0) {
                sb.append(", ");
            } else {
                sb.append('[');
            }

            sb.append(it.next());
        }

        return sb.toString() + ']';
    }
}

Other HSQLDB examples (source code examples)

Here is a short list of links related to this HSQLDB HashSet.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.