Cleaner.java

/*
 * Cleaner.java May 2004
 *
 * Copyright (C) 2004, Niall Gallagher <niallg@users.sf.net>
 *
 * 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.simpleframework.util.lease;

/**
 * The <code>Cleaner</code> represents an object that is used to clean up after
 * the keyed resource. Typically this is used when a <code>Lease</code>
 * referring a resource has expired meaning that any memory, file descriptors,
 * or other such limited data should be released for the keyed resource. The
 * resource keys used should be distinct over time to avoid conflicts.
 * 
 * @author Niall Gallagher
 * 
 * @see org.simpleframework.util.lease.Lease
 */
public interface Cleaner<T> {

    /**
     * This method is used to clean up after a the keyed resource. To ensure
     * that the leasing infrastructure operates properly this should not block
     * releasing resources. If required this should spawn a thread to perform
     * time consuming tasks.
     * 
     * @param key
     *            this is the key for the resource to clean
     */
    void clean(T key) throws Exception;
}