org.springframework.security.acls.afterinvocation.ArrayFilterer Maven / Gradle / Ivy
/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.security.acls.afterinvocation;
import java.lang.reflect.Array;
import java.util.HashSet;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* A filter used to filter arrays.
*
* @author Ben Alex
* @author Paulo Neves
*/
class ArrayFilterer implements Filterer {
// ~ Static fields/initializers
// =====================================================================================
protected static final Log logger = LogFactory.getLog(ArrayFilterer.class);
// ~ Instance fields
// ================================================================================================
private final Set removeList;
private final T[] list;
// ~ Constructors
// ===================================================================================================
ArrayFilterer(T[] list) {
this.list = list;
// Collect the removed objects to a HashSet so that
// it is fast to lookup them when a filtered array
// is constructed.
removeList = new HashSet();
}
// ~ Methods
// ========================================================================================================
/**
*
* @see org.springframework.security.acls.afterinvocation.Filterer#getFilteredObject()
*/
@SuppressWarnings("unchecked")
public T[] getFilteredObject() {
// Recreate an array of same type and filter the removed objects.
int originalSize = list.length;
int sizeOfResultingList = originalSize - removeList.size();
T[] filtered = (T[]) Array.newInstance(list.getClass().getComponentType(),
sizeOfResultingList);
for (int i = 0, j = 0; i < list.length; i++) {
T object = list[i];
if (!removeList.contains(object)) {
filtered[j] = object;
j++;
}
}
if (logger.isDebugEnabled()) {
logger.debug("Original array contained " + originalSize
+ " elements; now contains " + sizeOfResultingList + " elements");
}
return filtered;
}
/**
*
* @see org.springframework.security.acls.afterinvocation.Filterer#iterator()
*/
public Iterator iterator() {
return new Iterator() {
private int index = 0;
public boolean hasNext() {
return index < list.length;
}
public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return list[index++];
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
/**
*
* @see org.springframework.security.acls.afterinvocation.Filterer#remove(java.lang.Object)
*/
public void remove(T object) {
removeList.add(object);
}
}