001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.geronimo.kernel.classloader;
018
019 import java.net.URL;
020 import java.io.InputStream;
021 import java.io.IOException;
022 import java.util.jar.Manifest;
023 import java.util.jar.Attributes;
024 import java.security.cert.Certificate;
025
026 /**
027 * This is a handle (a connection) to some resource, which may
028 * be a class, native library, text file, image, etc. Handles are returned
029 * by a ResourceFinder. A resource handle allows easy access to the resource data
030 * (using methods {@link #getInputStream} or {@link #getBytes}) as well as
031 * access resource metadata, such as attributes, certificates, etc.
032 * <p/>
033 * As soon as the handle is no longer in use, it should be explicitly
034 * {@link #close}d, similarly to I/O streams.
035 *
036 * @version $Rev: 706640 $ $Date: 2008-10-21 14:44:05 +0000 (Tue, 21 Oct 2008) $
037 */
038 public interface ResourceHandle {
039 /**
040 * Return the name of the resource. The name is a "/"-separated path
041 * name that identifies the resource.
042 */
043 String getName();
044
045 /**
046 * Returns the URL of the resource.
047 */
048 URL getUrl();
049
050 /**
051 * Does this resource refer to a directory. Directory resources are commly used
052 * as the basis for a URL in client application. A directory resource has 0 bytes for it's content.
053 */
054 boolean isDirectory();
055
056 /**
057 * Returns the CodeSource URL for the class or resource.
058 */
059 URL getCodeSourceUrl();
060
061 /**
062 * Returns and InputStream for reading this resource data.
063 */
064 InputStream getInputStream() throws IOException;
065
066 /**
067 * Returns the length of this resource data, or -1 if unknown.
068 */
069 int getContentLength();
070
071 /**
072 * Returns this resource data as an array of bytes.
073 */
074 byte[] getBytes() throws IOException;
075
076 /**
077 * Returns the Manifest of the JAR file from which this resource
078 * was loaded, or null if none.
079 */
080 Manifest getManifest() throws IOException;
081
082 /**
083 * Return the Certificates of the resource, or null if none.
084 */
085 Certificate[] getCertificates();
086
087 /**
088 * Return the Attributes of the resource, or null if none.
089 */
090 Attributes getAttributes() throws IOException;
091
092 /**
093 * Closes a connection to the resource indentified by this handle. Releases
094 * any I/O objects associated with the handle.
095 */
096 void close();
097 }