/*
GNU LESSER GENERAL PUBLIC LICENSE
Copyright (C) 2006 The Lobo Project
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Contact info: lobochief@users.sourceforge.net
*/
/*
* Created on Apr 17, 2005
*/
package org.lobobrowser.util;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Iterator;
import java.util.function.Consumer;
/**
* @author J. H. S.
*/
public class ArrayUtilities {
/**
*
*/
private ArrayUtilities() {
super();
}
public static <T> T[] copy(final Collection<T> collection, final Class<T> clazz) {
@SuppressWarnings("unchecked")
final T[] castedArray = (T[]) Array.newInstance(clazz, collection.size());
return collection.toArray(castedArray);
}
/**
* Slightly more efficient version of the below version. Since it doesn't need
* to create an array if size is zero. But that is so only if the passed array
* is a static zero sized array
*/
public static <T> T[] copySynched(final Collection<T> collection, final Object syncObj, final T[] initArray) {
synchronized (syncObj) {
return collection.toArray(initArray);
}
}
public static <T> T[] copySynched(final Collection<T> collection, final Object syncObj, final Class<T> clazz) {
synchronized (syncObj) {
return copy(collection, clazz);
}
}
/**
* For each element of collection, the supplied function is called. The
* collection is copied in a synchronized block, to avoid concurrent
* modifications.
*
* @param syncObj
* The object to synchronize upon.
* @param func
* The function to call on each element.
*/
public static <T, E extends Throwable> void forEachSynched(final Collection<T> collection, final Object syncObj,
final Consumer<T> consumer) throws E {
if (collection.size() > 0) {
@SuppressWarnings("unchecked")
final Class<T> clazz = (Class<T>) collection.iterator().next().getClass();
final T[] copy = copySynched(collection, syncObj, clazz);
for (final T element : copy) {
consumer.accept(element);
}
}
}
public static <T> Iterator<T> iterator(final T[] array, final int offset, final int length) {
return new ArrayIterator<>(array, offset, length);
}
private static class ArrayIterator<T> implements Iterator<T> {
private final T[] array;
private final int top;
private int offset;
public ArrayIterator(final T[] array, final int offset, final int length) {
this.array = array;
this.offset = offset;
this.top = offset + length;
}
/*
* (non-Javadoc)
*
* @see java.util.Iterator#hasNext()
*/
public boolean hasNext() {
return this.offset < this.top;
}
/*
* (non-Javadoc)
*
* @see java.util.Iterator#next()
*/
public T next() {
return this.array[this.offset++];
}
/*
* (non-Javadoc)
*
* @see java.util.Iterator#remove()
*/
public void remove() {
throw new UnsupportedOperationException();
}
}
public static <T> boolean contains(final T[] ts, final T t) {
for (final T e: ts) {
if (java.util.Objects.equals(e, t)) {
return true;
}
}
return false;
}
}