1/*
2 * Copyright 2008 Netflix, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package net.oauth.http;
18
19import java.io.IOException;
20import java.io.InputStream;
21import java.util.Map;
22import java.util.zip.GZIPInputStream;
23import java.util.zip.InflaterInputStream;
24
25/**
26 * A decorator that handles Content-Encoding.
27 * @hide
28 */
29public class HttpMessageDecoder extends HttpResponseMessage {
30
31    /**
32     * Decode the given message if necessary and possible.
33     *
34     * @return a decorator that decodes the body of the given message; or the
35     *         given message if this class can't decode it.
36     */
37    public static HttpResponseMessage decode(HttpResponseMessage message)
38            throws IOException {
39        if (message != null) {
40            String encoding = getEncoding(message);
41            if (encoding != null) {
42                return new HttpMessageDecoder(message, encoding);
43            }
44        }
45        return message;
46    }
47
48    public static final String GZIP = "gzip";
49    public static final String DEFLATE = "deflate";
50    public static final String ACCEPTED = GZIP + "," + DEFLATE;
51
52    private static String getEncoding(HttpMessage message) {
53        String encoding = message.getHeader(CONTENT_ENCODING);
54        if (encoding == null) {
55            // That's easy.
56        } else if (GZIP.equalsIgnoreCase(encoding)
57                || ("x-" + GZIP).equalsIgnoreCase(encoding)) {
58            return GZIP;
59        } else if (DEFLATE.equalsIgnoreCase(encoding)) {
60            return DEFLATE;
61        }
62        return null;
63    }
64
65    private HttpMessageDecoder(HttpResponseMessage in, String encoding)
66            throws IOException {
67        super(in.method, in.url);
68        this.headers.addAll(in.headers);
69        removeHeaders(CONTENT_ENCODING); // handled here
70        removeHeaders(CONTENT_LENGTH); // unpredictable
71        InputStream body = in.getBody();
72        if (body != null) {
73            if (encoding == GZIP) {
74                body = new GZIPInputStream(body);
75            } else if (encoding == DEFLATE) {
76                body = new InflaterInputStream(body);
77            } else {
78                assert false;
79            }
80        }
81        this.body = body;
82        this.in = in;
83    }
84
85    private final HttpResponseMessage in;
86
87    @Override
88    public void dump(Map<String, Object> into) throws IOException {
89        in.dump(into);
90    }
91
92    @Override
93    public int getStatusCode() throws IOException {
94        return in.getStatusCode();
95    }
96
97}
98