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 2016 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 org.atmosphere.nettosphere; import io.netty.buffer.Unpooled; import io.netty.channel.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelProgressiveFuture; import io.netty.channel.ChannelProgressiveFutureListener; import io.netty.channel.DefaultFileRegion; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.TooLongFrameException; import io.netty.handler.codec.http.DefaultFullHttpResponse; import io.netty.handler.codec.http.DefaultHttpResponse; import io.netty.handler.codec.http.FullHttpRequest; import io.netty.handler.codec.http.FullHttpResponse; import io.netty.handler.codec.http.HttpChunkedInput; import io.netty.handler.codec.http.HttpHeaders; import io.netty.handler.codec.http.HttpResponse; import io.netty.handler.codec.http.HttpResponseEncoder; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.handler.codec.http.LastHttpContent; import io.netty.handler.ssl.SslHandler; import io.netty.handler.stream.ChunkedFile; import io.netty.util.AttributeKey; import io.netty.util.CharsetUtil; import org.atmosphere.nettosphere.util.MimeType; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.io.FileNotFoundException; import java.io.RandomAccessFile; import java.io.UnsupportedEncodingException; import java.net.URLDecoder; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.List; import java.util.Locale; import java.util.TimeZone; import java.util.regex.Pattern; import static io.netty.handler.codec.http.HttpHeaders.Names.CACHE_CONTROL; import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE; import static io.netty.handler.codec.http.HttpHeaders.Names.DATE; import static io.netty.handler.codec.http.HttpHeaders.Names.EXPIRES; import static io.netty.handler.codec.http.HttpHeaders.Names.IF_MODIFIED_SINCE; import static io.netty.handler.codec.http.HttpHeaders.Names.LAST_MODIFIED; import static io.netty.handler.codec.http.HttpHeaders.Names.LOCATION; import static io.netty.handler.codec.http.HttpMethod.GET; import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST; import static io.netty.handler.codec.http.HttpResponseStatus.FOUND; import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR; import static io.netty.handler.codec.http.HttpResponseStatus.METHOD_NOT_ALLOWED; import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND; import static io.netty.handler.codec.http.HttpResponseStatus.NOT_MODIFIED; import static io.netty.handler.codec.http.HttpResponseStatus.OK; 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 final List<String> paths; private String defaultContentType = "text/html"; public HttpStaticFileServerHandler(List<String> paths) { this.paths = paths; } @Override public void channelRead0(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception { if (!request.getDecoderResult().isSuccess()) { sendError(ctx, BAD_REQUEST, request); return; } if (request.getMethod() != GET) { sendError(ctx, METHOD_NOT_ALLOWED, request); return; } File file = null; RandomAccessFile raf = null; boolean found = true; for (String p : paths) { String path = p + sanitizeUri(request.getUri()); if (path.endsWith("/") || path.endsWith(File.separator)) { path += "index.html"; } if (path.endsWith("/favicon.ico") || path.endsWith(File.separator)) { request.headers().add(SERVICED, "true"); found = false; continue; } file = new File(path); if (file.isHidden() || !file.exists() || !file.isFile()) { found = false; continue; } // if (file.isDirectory()) { // if (uri.endsWith("/")) { // sendListing(ctx, file); // } else { // sendRedirect(ctx, uri + '/'); // } // return; // } try { raf = new RandomAccessFile(file, "r"); found = true; break; } catch (FileNotFoundException ignore) { sendError(ctx, NOT_FOUND, request); return; } } if (!found) { sendError(ctx, NOT_FOUND, request); return; } request.headers().add(SERVICED, "true"); // Cache Validation String ifModifiedSince = request.headers().get(IF_MODIFIED_SINCE); if (ifModifiedSince != null && !ifModifiedSince.isEmpty()) { SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US); Date ifModifiedSinceDate = dateFormatter.parse(ifModifiedSince); // Only compare up to the second because the datetime format we send to the client // does not have milliseconds long ifModifiedSinceDateSeconds = ifModifiedSinceDate.getTime() / 1000; long fileLastModifiedSeconds = file.lastModified() / 1000; if (ifModifiedSinceDateSeconds == fileLastModifiedSeconds) { sendNotModified(ctx); return; } } long fileLength = raf.length(); ctx.pipeline().addBefore(BridgeRuntime.class.getName(), "encoder", new HttpResponseEncoder()); HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK); HttpHeaders.setContentLength(response, fileLength); contentType(request, response, file); setDateAndCacheHeaders(response, file); // if (HttpHeaders.isKeepAlive(request)) { // response.headers().set(CONNECTION, HttpHeaders.Values.KEEP_ALIVE); // } // Write the initial line and the header. ctx.write(response); // Write the content. ChannelFuture sendFileFuture; ChannelFuture lastContentFuture; if (ctx.pipeline().get(SslHandler.class) == null) { sendFileFuture = ctx.write(new DefaultFileRegion(raf.getChannel(), 0, fileLength), ctx.newProgressivePromise()); // Write the end marker. lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT); } else { sendFileFuture = ctx.writeAndFlush(new HttpChunkedInput(new ChunkedFile(raf, 0, fileLength, 8192)), ctx.newProgressivePromise()); // HttpChunkedInput will write the end marker (LastHttpContent) for us. lastContentFuture = sendFileFuture; } sendFileFuture.addListener(new ChannelProgressiveFutureListener() { @Override public void operationProgressed(ChannelProgressiveFuture future, long progress, long total) { if (total < 0) { // total unknown logger.trace(future.channel() + " Transfer progress: " + progress); } else { logger.trace(future.channel() + " Transfer progress: " + progress + " / " + total); } } @Override public void operationComplete(ChannelProgressiveFuture future) { logger.trace(future.channel() + " Transfer complete."); } }); // Close the connection when the whole content is written out. lastContentFuture.addListener(ChannelFutureListener.CLOSE); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable t) { Channel ch = ctx.channel(); // Prevent recursion when the client close the connection during a write operation. In that // scenario the sendError will be invoked, but will fail since the channel has already been closed // For an unknown reason, if (ch.attr(ATTACHMENT) != null && Error.class.isAssignableFrom(ch.attr(ATTACHMENT).get().getClass())) { return; } Throwable cause = t.getCause(); if (cause instanceof TooLongFrameException) { sendError(ctx, BAD_REQUEST, null); return; } ch.attr(ATTACHMENT).set(new Error()); if (ch.isOpen()) { sendError(ctx, INTERNAL_SERVER_ERROR, null); } if (ctx.channel().isActive()) { sendError(ctx, INTERNAL_SERVER_ERROR, null); } } private static final Pattern INSECURE_URI = Pattern.compile(".*[<>&\"].*"); protected String sanitizeUri(String uri) { try { uri = URLDecoder.decode(uri, "UTF-8"); } catch (UnsupportedEncodingException e) { try { uri = URLDecoder.decode(uri, "ISO-8859-1"); } catch (UnsupportedEncodingException e1) { throw new Error(); } } uri = uri.replace('/', File.separatorChar); if (uri.contains(File.separator + ".") || uri.contains("." + File.separator) || uri.startsWith(".") || uri.endsWith(".")) { return null; } int pos = uri.indexOf("?"); if (pos != -1) { uri = uri.substring(0, pos); } return uri; } 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); } } }