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. */ /* * Copyright 2015 Async-IO.org * * Licensed 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.dempe.ketty.srv.http; import com.dempe.ketty.srv.uitl.MimeType; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.http.*; import io.netty.util.AttributeKey; import io.netty.util.CharsetUtil; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.text.SimpleDateFormat; import java.util.*; import java.util.regex.Pattern; import static io.netty.handler.codec.http.HttpHeaders.Names.*; import static io.netty.handler.codec.http.HttpResponseStatus.FOUND; import static io.netty.handler.codec.http.HttpResponseStatus.NOT_MODIFIED; import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1; /** * A simple handler that serves incoming HTTP requests to send their respective * HTTP responses. It also implements {@code 'If-Modified-Since'} header to * take advantage of browser cache, as described in * <a href="http://tools.ietf.org/html/rfc2616#section-14.25">RFC 2616</a>. * <p/> * <h3>How Browser Caching Works</h3> * <p/> * Web browser caching works with HTTP headers as illustrated by the following * sample: * <ol> * <li>Request #1 returns the content of {@code /file1.txt}.</li> * <li>Contents of {@code /file1.txt} is cached by the browser.</li> * <li>Request #2 for {@code /file1.txt} does return the contents of the * file again. Rather, a 304 Not Modified is returned. This tells the * browser to use the contents stored in its cache.</li> * <li>The server knows the file has not been modified because the * {@code If-Modified-Since} date is the same as the file's last * modified date.</li> * </ol> * <p/> * <pre> * Request #1 Headers * =================== * GET /file1.txt HTTP/1.1 * * Response #1 Headers * =================== * HTTP/1.1 200 OK * Date: Tue, 01 Mar 2011 22:44:26 GMT * Last-Modified: Wed, 30 Jun 2010 21:36:48 GMT * Expires: Tue, 01 Mar 2012 22:44:26 GMT * Cache-Control: private, max-age=31536000 * * Request #2 Headers * =================== * GET /file1.txt HTTP/1.1 * If-Modified-Since: Wed, 30 Jun 2010 21:36:48 GMT * * Response #2 Headers * =================== * HTTP/1.1 304 Not Modified * Date: Tue, 01 Mar 2011 22:44:28 GMT * * </pre> */ public class HttpStaticFileServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> { private static final Logger logger = LoggerFactory.getLogger(HttpStaticFileServerHandler.class); public static final String HTTP_DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss zzz"; public static final String HTTP_DATE_GMT_TIMEZONE = "GMT"; public static final int HTTP_CACHE_SECONDS = 60; public static final AttributeKey<Object> ATTACHMENT = AttributeKey .valueOf("HttpStaticFileServerHandler.attachment"); public final static String STATIC_MAPPING = SimpleChannelInboundHandler.class.getName() + ".staticMapping"; public final static String SERVICED = SimpleChannelInboundHandler.class.getName() + ".serviced"; private String defaultContentType = "text/html"; private static final Pattern INSECURE_URI = Pattern.compile(".*[<>&\"].*"); public static void sendRedirect(ChannelHandlerContext ctx, String newUri) { FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, FOUND); response.headers().set(LOCATION, newUri); // Close the connection as soon as the error message is sent. ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE); } public void sendError(ChannelHandlerContext ctx, HttpResponseStatus status, FullHttpRequest request) { FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, status, Unpooled.copiedBuffer("Failure: " + status + "\r\n", CharsetUtil.UTF_8)); response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8"); // Close the connection as soon as the error message is sent. ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE); } /** * When file timestamp is the same as what the browser is sending up, send a "304 Not Modified" * * @param ctx Context */ public static void sendNotModified(ChannelHandlerContext ctx) { FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, NOT_MODIFIED); setDateHeader(response); // Close the connection as soon as the error message is sent. ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE); } /** * Sets the Date header for the HTTP response * * @param response HTTP response */ public static void setDateHeader(FullHttpResponse response) { SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US); dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE)); Calendar time = new GregorianCalendar(); response.headers().set(DATE, dateFormatter.format(time.getTime())); } /** * Sets the Date and Cache headers for the HTTP Response * * @param response HTTP response * @param fileToCache file to extract content type */ public static void setDateAndCacheHeaders(HttpResponse response, File fileToCache) { SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US); dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE)); // Date header Calendar time = new GregorianCalendar(); response.headers().set(DATE, dateFormatter.format(time.getTime())); // Add cache headers time.add(Calendar.SECOND, HTTP_CACHE_SECONDS); response.headers().set(EXPIRES, dateFormatter.format(time.getTime())); response.headers().set(CACHE_CONTROL, "private, max-age=" + HTTP_CACHE_SECONDS); response.headers().set(LAST_MODIFIED, dateFormatter.format(new Date(fileToCache.lastModified()))); } protected void contentType(FullHttpRequest request, HttpResponse response, File resource) { String substr; String uri = request.getUri(); int dot = uri.lastIndexOf("."); if (dot < 0) { substr = resource.toString(); dot = substr.lastIndexOf("."); } else { substr = uri; } if (dot > 0) { String ext = substr.substring(dot + 1); int queryString = ext.indexOf("?"); if (queryString > 0) { ext.substring(0, queryString); } String contentType = MimeType.get(ext, defaultContentType); response.headers().add(HttpHeaders.Names.CONTENT_TYPE, contentType); } else { response.headers().add(HttpHeaders.Names.CONTENT_TYPE, defaultContentType); } } @Override protected void messageReceived(ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception { ctx.fireChannelRead(msg); } }