| /* |
| * Copyright (c) 1995, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.net; |
| |
| import java.io.IOException; |
| |
| /** |
| * The abstract class <code>ContentHandler</code> is the superclass |
| * of all classes that read an <code>Object</code> from a |
| * <code>URLConnection</code>. |
| * <p> |
| * An application does not generally call the |
| * <code>getContent</code> method in this class directly. Instead, an |
| * application calls the <code>getContent</code> method in class |
| * <code>URL</code> or in <code>URLConnection</code>. |
| * The application's content handler factory (an instance of a class that |
| * implements the interface <code>ContentHandlerFactory</code> set |
| * up by a call to <code>setContentHandler</code>) is |
| * called with a <code>String</code> giving the MIME type of the |
| * object being received on the socket. The factory returns an |
| * instance of a subclass of <code>ContentHandler</code>, and its |
| * <code>getContent</code> method is called to create the object. |
| * <p> |
| * If no content handler could be found, URLConnection will |
| * look for a content handler in a user-defineable set of places. |
| * By default it looks in sun.net.www.content, but users can define a |
| * vertical-bar delimited set of class prefixes to search through in |
| * addition by defining the java.content.handler.pkgs property. |
| * The class name must be of the form: |
| * <pre> |
| * {package-prefix}.{major}.{minor} |
| * e.g. |
| * YoyoDyne.experimental.text.plain |
| * </pre> |
| * If the loading of the content handler class would be performed by |
| * a classloader that is outside of the delegation chain of the caller, |
| * the JVM will need the RuntimePermission "getClassLoader". |
| * |
| * @author James Gosling |
| * @see java.net.ContentHandler#getContent(java.net.URLConnection) |
| * @see java.net.ContentHandlerFactory |
| * @see java.net.URL#getContent() |
| * @see java.net.URLConnection |
| * @see java.net.URLConnection#getContent() |
| * @see java.net.URLConnection#setContentHandlerFactory(java.net.ContentHandlerFactory) |
| * @since JDK1.0 |
| */ |
| abstract public class ContentHandler { |
| /** |
| * Given a URL connect stream positioned at the beginning of the |
| * representation of an object, this method reads that stream and |
| * creates an object from it. |
| * |
| * @param urlc a URL connection. |
| * @return the object read by the <code>ContentHandler</code>. |
| * @exception IOException if an I/O error occurs while reading the object. |
| */ |
| abstract public Object getContent(URLConnection urlc) throws IOException; |
| |
| /** |
| * Given a URL connect stream positioned at the beginning of the |
| * representation of an object, this method reads that stream and |
| * creates an object that matches one of the types specified. |
| * |
| * The default implementation of this method should call getContent() |
| * and screen the return type for a match of the suggested types. |
| * |
| * @param urlc a URL connection. |
| * @param classes an array of types requested |
| * @return the object read by the <code>ContentHandler</code> that is |
| * the first match of the suggested types. |
| * null if none of the requested are supported. |
| * @exception IOException if an I/O error occurs while reading the object. |
| * @since 1.3 |
| */ |
| public Object getContent(URLConnection urlc, Class[] classes) throws IOException { |
| Object obj = getContent(urlc); |
| |
| for (int i = 0; i < classes.length; i++) { |
| if (classes[i].isInstance(obj)) { |
| return obj; |
| } |
| } |
| return null; |
| } |
| |
| } |