1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.handler.codec.http;
17
18 import io.netty.buffer.ByteBuf;
19 import io.netty.buffer.ByteBufUtil;
20
21 import static io.netty.handler.codec.http.HttpConstants.*;
22
23 /**
24 * Encodes an {@link HttpResponse} or an {@link HttpContent} into
25 * a {@link ByteBuf}.
26 */
27 public class HttpResponseEncoder extends HttpObjectEncoder<HttpResponse> {
28
29 @Override
30 public boolean acceptOutboundMessage(Object msg) throws Exception {
31 return super.acceptOutboundMessage(msg) && !(msg instanceof HttpRequest);
32 }
33
34 @Override
35 protected void encodeInitialLine(ByteBuf buf, HttpResponse response) throws Exception {
36 response.protocolVersion().encode(buf);
37 buf.writeByte(SP);
38 response.status().encode(buf);
39 ByteBufUtil.writeShortBE(buf, CRLF_SHORT);
40 }
41
42 @Override
43 protected void sanitizeHeadersBeforeEncode(HttpResponse msg, boolean isAlwaysEmpty) {
44 if (isAlwaysEmpty) {
45 HttpResponseStatus status = msg.status();
46 if (status.codeClass() == HttpStatusClass.INFORMATIONAL ||
47 status.code() == HttpResponseStatus.NO_CONTENT.code()) {
48
49 // Stripping Content-Length:
50 // See https://tools.ietf.org/html/rfc7230#section-3.3.2
51 msg.headers().remove(HttpHeaderNames.CONTENT_LENGTH);
52
53 // Stripping Transfer-Encoding:
54 // See https://tools.ietf.org/html/rfc7230#section-3.3.1
55 msg.headers().remove(HttpHeaderNames.TRANSFER_ENCODING);
56 } else if (status.code() == HttpResponseStatus.RESET_CONTENT.code()) {
57
58 // Stripping Transfer-Encoding:
59 msg.headers().remove(HttpHeaderNames.TRANSFER_ENCODING);
60
61 // Set Content-Length: 0
62 // https://httpstatuses.com/205
63 msg.headers().setInt(HttpHeaderNames.CONTENT_LENGTH, 0);
64 }
65 }
66 }
67
68 @Override
69 protected boolean isContentAlwaysEmpty(HttpResponse msg) {
70 // Correctly handle special cases as stated in:
71 // https://tools.ietf.org/html/rfc7230#section-3.3.3
72 HttpResponseStatus status = msg.status();
73
74 if (status.codeClass() == HttpStatusClass.INFORMATIONAL) {
75
76 if (status.code() == HttpResponseStatus.SWITCHING_PROTOCOLS.code()) {
77 // We need special handling for WebSockets version 00 as it will include an body.
78 // Fortunally this version should not really be used in the wild very often.
79 // See https://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00#section-1.2
80 return msg.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_VERSION);
81 }
82 return true;
83 }
84 return status.code() == HttpResponseStatus.NO_CONTENT.code() ||
85 status.code() == HttpResponseStatus.NOT_MODIFIED.code() ||
86 status.code() == HttpResponseStatus.RESET_CONTENT.code();
87 }
88 }