1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.io.ByteArrayInputStream;
  25 import java.io.InputStream;
  26 import java.net.ContentHandlerFactory;
  27 import java.net.URL;
  28 import java.net.URLConnection;
  29 import java.net.URLStreamHandler;
  30 import java.net.URLStreamHandlerFactory;
  31 
  32 public class Test {
  33 
  34     public static void main(String[] args) throws Exception {
  35         if (args.length > 0) {
  36             String fqn = args[0];
  37 
  38             @SuppressWarnings("unchecked")
  39             Class<? extends ContentHandlerFactory> c =
  40                     (Class<? extends ContentHandlerFactory>) Class.forName(fqn);
  41 
  42             ContentHandlerFactory f = c.newInstance();
  43 
  44             URLConnection.setContentHandlerFactory(f);
  45         }
  46 
  47         // One does not simply use a ContentHandler...
  48         // From an end user perspective ContentHandler is used indirectly
  49         // and it's more like SPI rather than API. So there's a certain amount
  50         // of preparations needs to be done beforehand.
  51 
  52         URLStreamHandlerFactory streamHandlerFactory =
  53                 (protocol) ->
  54                         new URLStreamHandler() {
  55                             @Override
  56                             protected URLConnection openConnection(URL u) {
  57                                 return newUrlConnection(u);
  58                             }
  59                         };
  60 
  61         URL.setURLStreamHandlerFactory(streamHandlerFactory);
  62 
  63         // Finally
  64         Object content = new URL("whatever:").getContent();
  65 
  66         System.out.println("Content class is: " + content.getClass());
  67     }
  68 
  69     private static URLConnection newUrlConnection(URL u) {
  70         return new URLConnection(u) {
  71             @Override public void connect() { }
  72 
  73             @Override
  74             public InputStream getInputStream() { return null; }
  75 
  76             @Override public String getContentType() { return "text/plain"; }
  77         };
  78     }
  79 }