001/*
002 * Copyright (C) 2014 Jörg Prante
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.xbib.elasticsearch.plugin.jdbc.classloader;
017
018import java.net.URL;
019import java.util.Enumeration;
020
021/**
022 * Abstraction of resource searching policy. Given resource name, the resource
023 * finder performs implementation-specific lookup, and, if it is able to locate
024 * the resource, returns the {@link AbstractResourceHandle handle(s)} or URL(s)
025 * of it.
026 */
027public interface ResourceFinder {
028
029    /**
030     * Find the resource by name and return URL of it if found.
031     *
032     * @param name the resource name
033     * @return resource URL or null if resource was not found
034     */
035    URL findResource(String name);
036
037    /**
038     * Find all resources with given name and return enumeration of their URLs.
039     *
040     * @param name the resource name
041     * @return enumeration of resource URLs (possibly empty).
042     */
043    Enumeration<URL> findResources(String name);
044
045    /**
046     * Get the resource by name and, if found, open connection to it and return
047     * the {@link AbstractResourceHandle handle} of it.
048     *
049     * @param name the resource name
050     * @return resource handle or null if resource was not found
051     */
052    ResourceHandle getResource(String name);
053}