1 /*

     2  * Copyright (c) 2015, 2017, 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package jdk.incubator.http;

    27 

    28 import java.io.IOException;

    29 import java.io.UncheckedIOException;

    30 import java.net.URI;

    31 import jdk.incubator.http.internal.common.Utils;

    32 

    33 class RedirectFilter implements HeaderFilter {

    34 

    35     HttpRequestImpl request;

    36     HttpClientImpl client;

    37     HttpClient.Redirect policy;

    38     String method;

    39     MultiExchange<?> exchange;

    40     static final int DEFAULT_MAX_REDIRECTS = 5;

    41     URI uri;

    42 

    43     static final int max_redirects = Utils.getIntegerNetProperty(

    44             "jdk.httpclient.redirects.retrylimit", DEFAULT_MAX_REDIRECTS

    45     );

    46 

    47     // A public no-arg constructor is required by FilterFactory

    48     public RedirectFilter() {}

    49 

    50     @Override

    51     public synchronized void request(HttpRequestImpl r, MultiExchange<?> e) throws IOException {

    52         this.request = r;

    53         this.client = e.client();

    54         this.policy = client.followRedirects();

    55 

    56         this.method = r.method();

    57         this.uri = r.uri();

    58         this.exchange = e;

    59     }

    60 

    61     @Override

    62     public synchronized HttpRequestImpl response(Response r) throws IOException {

    63         return handleResponse(r);

    64     }

    65 

    66     /**

    67      * checks to see if new request needed and returns it.

    68      * Null means response is ok to return to user.

    69      */

    70     private HttpRequestImpl handleResponse(Response r) {

    71         int rcode = r.statusCode();

    72         if (rcode == 200 || policy == HttpClient.Redirect.NEVER) {

    73             return null;

    74         }

    75         if (rcode >= 300 && rcode <= 399) {

    76             URI redir = getRedirectedURI(r.headers());

    77             if (canRedirect(redir) && ++exchange.numberOfRedirects < max_redirects) {

    78                 //System.out.println("Redirecting to: " + redir);

    79                 return new HttpRequestImpl(redir, method, request);

    80             } else {

    81                 //System.out.println("Redirect: giving up");

    82                 return null;

    83             }

    84         }

    85         return null;

    86     }

    87 

    88     private URI getRedirectedURI(HttpHeaders headers) {

    89         URI redirectedURI;

    90         redirectedURI = headers.firstValue("Location")

    91                 .map(URI::create)

    92                 .orElseThrow(() -> new UncheckedIOException(

    93                         new IOException("Invalid redirection")));

    94 

    95         // redirect could be relative to original URL, but if not

    96         // then redirect is used.

    97         redirectedURI = uri.resolve(redirectedURI);

    98         return redirectedURI;

    99     }

   100 

   101     private boolean canRedirect(URI redir) {

   102         String newScheme = redir.getScheme();

   103         String oldScheme = uri.getScheme();

   104         switch (policy) {

   105             case ALWAYS:

   106                 return true;

   107             case NEVER:

   108                 return false;

   109             case SECURE:

   110                 return newScheme.equalsIgnoreCase("https");

   111             case SAME_PROTOCOL:

   112                 return newScheme.equalsIgnoreCase(oldScheme);

   113             default:

   114                 throw new InternalError();

   115         }

   116     }

   117 }