Java tutorial
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package com.phei.netty.nio.http.cors; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.logging.LogLevel; import io.netty.handler.logging.LoggingHandler; import io.netty.handler.ssl.SslContext; import io.netty.handler.ssl.util.SelfSignedCertificate; /** * This example server aims to demonstrate * <a href="http://www.w3.org/TR/cors/">Cross Origin Resource Sharing</a> (CORS) in Netty. * It does not have a client like most of the other examples, but instead has * a html page that is loaded to try out CORS support in a web brower. * <p> * * CORS is configured in {@link HttpCorsServerInitializer} and by updating the config you can * try out various combinations, like using a specific origin instead of a * wildcard origin ('*'). * <p> * * The file {@code src/main/resources/cors/cors.html} contains a very basic example client * which can be used to try out different configurations. For example, you can add * custom headers to force a CORS preflight request to make the request fail. Then * to enable a successful request, configure the CorsHandler to allow that/those * request headers. * * <h2>Testing CORS</h2> * You can either load the file {@code src/main/resources/cors/cors.html} using a web server * or load it from the file system using a web browser. * * <h3>Using a web server</h3> * To test CORS support you can serve the file {@code src/main/resources/cors/cors.html} * using a web server. You can then add a new host name to your systems hosts file, for * example if you are on Linux you may update /etc/hosts to add an addtional name * for you local system: * <pre> * 127.0.0.1 localhost domain1.com * </pre> * Now, you should be able to access {@code http://domain1.com/cors.html} depending on how you * have configured you local web server the exact url may differ. * * <h3>Using a web browser</h3> * Open the file {@code src/main/resources/cors/cors.html} in a web browser. You should see * loaded page and in the text area the following message: * <pre> * 'CORS is not working' * </pre> * * If you inspect the headers being sent using your browser you'll see that the 'Origin' * request header is {@code 'null'}. This is expected and happens when you load a file from the * local file system. Netty can handle this by configuring the CorsHandler which is done * in the {@link HttpCorsServerInitializer}. * */ public final class HttpCorsServer { static final boolean SSL = System.getProperty("ssl") != null; static final int PORT = Integer.parseInt(System.getProperty("port", SSL ? "8443" : "8080")); public static void main(String[] args) throws Exception { // Configure SSL. final SslContext sslCtx; if (SSL) { SelfSignedCertificate ssc = new SelfSignedCertificate(); sslCtx = SslContext.newServerContext(ssc.certificate(), ssc.privateKey()); } else { sslCtx = null; } EventLoopGroup bossGroup = new NioEventLoopGroup(1); EventLoopGroup workerGroup = new NioEventLoopGroup(); try { ServerBootstrap b = new ServerBootstrap(); b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class) .handler(new LoggingHandler(LogLevel.INFO)).childHandler(new HttpCorsServerInitializer(sslCtx)); b.bind(PORT).sync().channel().closeFuture().sync(); } finally { bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } } }