/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.catalina.util;
import java.util.Collection;
import java.util.HashSet;
import org.apache.tomcat.util.res.StringManager;
/**
* Extended implementation of <strong>HashSet</strong> that includes a
* <code>locked</code> property. This class can be used to safely expose
* resource path sets to user classes without having to clone them in order
* to avoid modifications. When first created, a <code>ResourceMap</code>
* is not locked.
*
* @param <T> The type of elements in the Set
*
* @author Craig R. McClanahan
*/
public final class ResourceSet<T> extends HashSet<T> {
private static final long serialVersionUID = 1L;
// ----------------------------------------------------------- Constructors
/**
* Construct a new, empty set with the default initial capacity and
* load factor.
*/
public ResourceSet() {
super();
}
/**
* Construct a new, empty set with the specified initial capacity and
* default load factor.
*
* @param initialCapacity The initial capacity of this set
*/
public ResourceSet(int initialCapacity) {
super(initialCapacity);
}
/**
* Construct a new, empty set with the specified initial capacity and
* load factor.
*
* @param initialCapacity The initial capacity of this set
* @param loadFactor The load factor of this set
*/
public ResourceSet(int initialCapacity, float loadFactor) {
super(initialCapacity, loadFactor);
}
/**
* Construct a new set with the same contents as the existing collection.
*
* @param coll The collection whose contents we should copy
*/
public ResourceSet(Collection<T> coll) {
super(coll);
}
// ------------------------------------------------------------- Properties
/**
* The current lock state of this parameter map.
*/
private boolean locked = false;
/**
* @return the locked state of this parameter map.
*/
public boolean isLocked() {
return this.locked;
}
/**
* Set the locked state of this parameter map.
*
* @param locked The new locked state
*/
public void setLocked(boolean locked) {
this.locked = locked;
}
/**
* The string manager for this package.
*/
private static final StringManager sm =
StringManager.getManager("org.apache.catalina.util");
// --------------------------------------------------------- Public Methods
/**
* Add the specified element to this set if it is not already present.
* Return <code>true</code> if the element was added.
*
* @param o The object to be added
*
* @exception IllegalStateException if this ResourceSet is locked
*/
@Override
public boolean add(T o) {
if (locked)
throw new IllegalStateException
(sm.getString("resourceSet.locked"));
return super.add(o);
}
/**
* Remove all of the elements from this set.
*
* @exception IllegalStateException if this ResourceSet is locked
*/
@Override
public void clear() {
if (locked)
throw new IllegalStateException
(sm.getString("resourceSet.locked"));
super.clear();
}
/**
* Remove the given element from this set if it is present.
* Return <code>true</code> if the element was removed.
*
* @param o The object to be removed
*
* @exception IllegalStateException if this ResourceSet is locked
*/
@Override
public boolean remove(Object o) {
if (locked)
throw new IllegalStateException
(sm.getString("resourceSet.locked"));
return super.remove(o);
}
}