Java tutorial
/** * Copyright 2016 AWACS Project. * * 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 io.awacs.server; import com.google.common.collect.ImmutableMap; import io.awacs.core.Configurable; import io.awacs.core.Configuration; import io.awacs.core.InitializationException; import io.awacs.core.Plugins; import io.awacs.core.transport.Server; import io.netty.bootstrap.ServerBootstrap; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.*; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.codec.http.*; import io.netty.handler.logging.LogLevel; import io.netty.handler.logging.LoggingHandler; import io.netty.handler.ssl.SslHandler; import io.netty.handler.stream.ChunkedFile; import io.netty.handler.stream.ChunkedWriteHandler; import io.netty.util.CharsetUtil; import javax.activation.MimetypesFileTypeMap; 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.*; import java.util.regex.Pattern; import static io.netty.handler.codec.http.HttpHeaders.Names.*; import static io.netty.handler.codec.http.HttpMethod.GET; import static io.netty.handler.codec.http.HttpResponseStatus.*; import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1; /** * Created by pixyonly on 8/24/16. */ public final class StaticResourceServer implements Server, Configurable { private EventLoopGroup boss; private EventLoopGroup worker; private String host; private int port; @Override public void setPlugins(Plugins plugins) { } @Override public void start() { ServerBootstrap bootstrap = new ServerBootstrap(); bootstrap.group(boss, worker).channel(NioServerSocketChannel.class) .handler(new LoggingHandler(LogLevel.INFO)).childHandler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { ch.pipeline().addLast(new HttpServerCodec()); ch.pipeline().addLast(new HttpObjectAggregator(65536)); ch.pipeline().addLast(new ChunkedWriteHandler()); ch.pipeline().addLast(new StaticResourceHandler(StaticResourceServer.this)); } }); try { bootstrap.bind(host, port).sync(); } catch (InterruptedException e) { stop(); } } @Override public void stop() { boss.shutdownGracefully(); worker.shutdownGracefully(); } @Override public void init(Configuration configuration) throws InitializationException { String serverName = configuration.getString(Configurations.SERVER_PREFIX); ImmutableMap<String, String> serverConfig = configuration .getSubProperties(Configurations.SERVER_PREFIX + "." + serverName + "."); host = serverConfig.getOrDefault(Configurations.HTTP_BIND_HOST, Configurations.DEFAULT_HTTP_BIND_HOST); port = Integer.parseInt( serverConfig.getOrDefault(Configurations.HTTP_BIND_PORT, Configurations.DEFAULT_HTTP_BIND_PORT)); int bossCore = Integer.parseInt( serverConfig.getOrDefault(Configurations.HTTP_BOSS_CORE, Configurations.DEFAULT_HTTP_BOSS_CORE)); int workerCore = Integer.parseInt(serverConfig.getOrDefault(Configurations.HTTP_WORKER_CORE, Configurations.DEFAULT_HTTP_WORKER_CORE)); boss = new NioEventLoopGroup(bossCore); worker = new NioEventLoopGroup(workerCore); } /** * Created by pixyonly on 8/24/16. */ public static class StaticResourceHandler extends SimpleChannelInboundHandler<FullHttpRequest> { 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; private StaticResourceServer owner; StaticResourceHandler(StaticResourceServer owner) { this.owner = owner; } @Override public void channelRead0(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception { if (!request.getDecoderResult().isSuccess()) { sendError(ctx, BAD_REQUEST); return; } if (request.getMethod() != GET) { sendError(ctx, METHOD_NOT_ALLOWED); return; } final String uri = request.getUri(); String path = sanitizeUri(uri); if (path == null) { sendError(ctx, FORBIDDEN); return; } if (isNavigation(uri)) { path = path + "/config.json"; } File file = new File(path); if (file.isHidden() || !file.exists()) { sendError(ctx, NOT_FOUND); return; } if (file.isDirectory()) { if (uri.endsWith("/")) { sendListing(ctx, file); } else { sendRedirect(ctx, uri + '/'); } return; } if (!file.isFile()) { sendError(ctx, FORBIDDEN); return; } // 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; } } RandomAccessFile raf; try { raf = new RandomAccessFile(file, "r"); } catch (FileNotFoundException ignore) { sendError(ctx, NOT_FOUND); return; } long fileLength = raf.length(); HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK); HttpHeaders.setContentLength(response, fileLength); setContentTypeHeader(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 System.err.println(future.channel() + " Transfer progress: " + progress); } else { System.err.println(future.channel() + " Transfer progress: " + progress + " / " + total); } } @Override public void operationComplete(ChannelProgressiveFuture future) { System.err.println(future.channel() + " Transfer complete."); } }); // Decide whether to close the connection or not. if (!HttpHeaders.isKeepAlive(request)) { // Close the connection when the whole content is written out. lastContentFuture.addListener(ChannelFutureListener.CLOSE); } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); if (ctx.channel().isActive()) { sendError(ctx, INTERNAL_SERVER_ERROR); } } private static final Pattern INSECURE_URI = Pattern.compile(".*[<>&\"].*"); private boolean isNavigation(String uri) { char[] chars = uri.toCharArray(); char cc = chars[0]; for (char c : chars) { cc ^= c; } return cc == 0; } private static String sanitizeUri(String uri) { // Decode the path. try { uri = URLDecoder.decode(uri, "UTF-8"); } catch (UnsupportedEncodingException e) { throw new Error(e); } if (uri.isEmpty() || uri.charAt(0) != '/') { return null; } // Convert file separators. uri = uri.replace('/', File.separatorChar); // Simplistic dumb security check. // You will have to do something serious in the production environment. if (uri.contains(File.separator + '.') || uri.contains('.' + File.separator) || uri.charAt(0) == '.' || uri.charAt(uri.length() - 1) == '.' || INSECURE_URI.matcher(uri).matches()) { return null; } // Convert to absolute path. return Configurations.getPluginPath() + uri; } private static final Pattern ALLOWED_FILE_NAME = Pattern.compile("[A-Za-z0-9][-_A-Za-z0-9\\.]*"); private static void sendListing(ChannelHandlerContext ctx, File dir) { FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK); response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8"); String dirPath = dir.getPath(); StringBuilder buf = new StringBuilder().append("<!DOCTYPE html>\r\n").append("<html><head><title>") .append("Listing of: ").append(dirPath).append("</title></head><body>\r\n") .append("<h3>Listing of: ").append(dirPath).append("</h3>\r\n") .append("<ul>").append("<li><a href=\"../\">..</a></li>\r\n"); for (File f : dir.listFiles()) { if (f.isHidden() || !f.canRead()) { continue; } String name = f.getName(); if (!ALLOWED_FILE_NAME.matcher(name).matches()) { continue; } buf.append("<li><a href=\"").append(name).append("\">").append(name).append("</a></li>\r\n"); } buf.append("</ul></body></html>\r\n"); ByteBuf buffer = Unpooled.copiedBuffer(buf, CharsetUtil.UTF_8); response.content().writeBytes(buffer); buffer.release(); // Close the connection as soon as the error message is sent. ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE); } private 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); } private static void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) { 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 */ private 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 */ private 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 */ private 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()))); } /** * Sets the content type header for the HTTP Response * * @param response HTTP response * @param file file to extract content type */ private static void setContentTypeHeader(HttpResponse response, File file) { MimetypesFileTypeMap mimeTypesMap = new MimetypesFileTypeMap(); response.headers().set(CONTENT_TYPE, mimeTypesMap.getContentType(file.getPath())); } } }