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 * 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, 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.example.http.cors;
17
18 import io.netty.channel.ChannelInitializer;
19 import io.netty.channel.ChannelPipeline;
20 import io.netty.channel.socket.SocketChannel;
21 import io.netty.handler.codec.http.HttpObjectAggregator;
22 import io.netty.handler.codec.http.HttpRequestDecoder;
23 import io.netty.handler.codec.http.HttpResponseEncoder;
24 import io.netty.handler.codec.http.cors.CorsConfig;
25 import io.netty.handler.codec.http.cors.CorsHandler;
26 import io.netty.handler.ssl.SslContext;
27 import io.netty.handler.stream.ChunkedWriteHandler;
28
29 /**
30 * Please refer to the {@link CorsConfig} javadocs for information about all the
31 * configuration options available.
32 *
33 * Below are some of configuration discussed in this example:
34 * <h3>Support only a specific origin</h3>
35 * To support a single origin instead of the wildcard use the following:
36 * <pre>
37 * CorsConfig corsConfig = CorsConfig.withOrigin("http://domain1.com")
38 * </pre>
39 *
40 * <h3>Enable loading from the file system</h3>
41 * To enable the server to handle an origin specified as 'null', which happens
42 * when a web browser loads a file from the local file system use the following:
43 * <pre>
44 * corsConfig.isNullOriginAllowed()
45 * </pre>
46 *
47 * <h3>Enable request headers</h3>
48 * To enable additional request headers:
49 * <pre>
50 * corsConfig.allowedRequestHeaders("custom-request-header")
51 * </pre>
52 *
53 * <h3>Expose response headers</h3>
54 * By default a browser only exposes the following simple header:
55 * <ul>
56 * <li>Cache-Control</li>
57 * <li>Content-Language</li>
58 * <li>Content-Type</li>
59 * <li>Expires</li>
60 * <li>Last-Modified</li>
61 * <li>Pragma</li>
62 * </ul>
63 * Any of the above response headers can be retrieved by:
64 * <pre>
65 * xhr.getResponseHeader("Content-Type");
66 * </pre>
67 * If you need to get access to other headers this must be enabled by the server, for example:
68 * <pre>
69 * corsConfig.exposedHeaders("custom-response-header");
70 * </pre>
71 */
72 public class HttpCorsServerInitializer extends ChannelInitializer<SocketChannel> {
73
74 private final SslContext sslCtx;
75
76 public HttpCorsServerInitializer(SslContext sslCtx) {
77 this.sslCtx = sslCtx;
78 }
79
80 @Override
81 public void initChannel(SocketChannel ch) {
82 CorsConfig corsConfig = CorsConfig.withAnyOrigin().build();
83 ChannelPipeline pipeline = ch.pipeline();
84 if (sslCtx != null) {
85 pipeline.addLast(sslCtx.newHandler(ch.alloc()));
86 }
87 pipeline.addLast(new HttpResponseEncoder());
88 pipeline.addLast(new HttpRequestDecoder());
89 pipeline.addLast(new HttpObjectAggregator(65536));
90 pipeline.addLast(new ChunkedWriteHandler());
91 pipeline.addLast(new CorsHandler(corsConfig));
92 pipeline.addLast(new OkResponseHandler());
93 }
94
95 }