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.netty5.example.http.cors;
17
18 import io.netty5.channel.ChannelInitializer;
19 import io.netty5.channel.ChannelPipeline;
20 import io.netty5.channel.socket.SocketChannel;
21 import io.netty5.handler.codec.http.HttpObjectAggregator;
22 import io.netty5.handler.codec.http.HttpRequestDecoder;
23 import io.netty5.handler.codec.http.HttpResponseEncoder;
24 import io.netty5.handler.codec.http.cors.CorsConfig;
25 import io.netty5.handler.codec.http.cors.CorsConfigBuilder;
26 import io.netty5.handler.codec.http.cors.CorsHandler;
27 import io.netty5.handler.ssl.SslContext;
28 import io.netty5.handler.stream.ChunkedWriteHandler;
29
30 /**
31 * Please refer to the {@link CorsConfig} javadocs for information about all the
32 * configuration options available.
33 *
34 * Below are some of configuration discussed in this example:
35 * <h3>Support only a specific origin</h3>
36 * To support a single origin instead of the wildcard use the following:
37 * <pre>
38 * CorsConfig corsConfig = CorsConfig.withOrigin("http://domain1.com")
39 * </pre>
40 *
41 * <h3>Enable loading from the file system</h3>
42 * To enable the server to handle an origin specified as 'null', which happens
43 * when a web browser loads a file from the local file system use the following:
44 * <pre>
45 * corsConfig.isNullOriginAllowed()
46 * </pre>
47 *
48 * <h3>Enable request headers</h3>
49 * To enable additional request headers:
50 * <pre>
51 * corsConfig.allowedRequestHeaders("custom-request-header")
52 * </pre>
53 *
54 * <h3>Expose response headers</h3>
55 * By default a browser only exposes the following simple header:
56 * <ul>
57 * <li>Cache-Control</li>
58 * <li>Content-Language</li>
59 * <li>Content-Type</li>
60 * <li>Expires</li>
61 * <li>Last-Modified</li>
62 * <li>Pragma</li>
63 * </ul>
64 * Any of the above response headers can be retrieved by:
65 * <pre>
66 * xhr.getResponseHeader("Content-Type");
67 * </pre>
68 * If you need to get access to other headers this must be enabled by the server, for example:
69 * <pre>
70 * corsConfig.exposedHeaders("custom-response-header");
71 * </pre>
72 */
73 public class HttpCorsServerInitializer extends ChannelInitializer<SocketChannel> {
74
75 private final SslContext sslCtx;
76
77 public HttpCorsServerInitializer(SslContext sslCtx) {
78 this.sslCtx = sslCtx;
79 }
80
81 @Override
82 public void initChannel(SocketChannel ch) {
83 CorsConfig corsConfig = CorsConfigBuilder.forAnyOrigin().allowNullOrigin().allowCredentials().build();
84 ChannelPipeline pipeline = ch.pipeline();
85 if (sslCtx != null) {
86 pipeline.addLast(sslCtx.newHandler(ch.bufferAllocator()));
87 }
88 pipeline.addLast(new HttpResponseEncoder());
89 pipeline.addLast(new HttpRequestDecoder());
90 pipeline.addLast(new HttpObjectAggregator(65536));
91 pipeline.addLast(new ChunkedWriteHandler());
92 pipeline.addLast(new CorsHandler(corsConfig));
93 pipeline.addLast(new OkResponseHandler());
94 }
95
96 }