Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF 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 org.apache.tajo; import io.netty.buffer.Unpooled; import io.netty.channel.*; import io.netty.handler.codec.TooLongFrameException; import io.netty.handler.codec.http.*; import io.netty.handler.ssl.SslHandler; import io.netty.handler.stream.ChunkedFile; import io.netty.util.CharsetUtil; import java.io.File; import java.io.FileNotFoundException; import java.io.RandomAccessFile; import java.io.UnsupportedEncodingException; import java.net.URLDecoder; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class HttpFileServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> { private final Log LOG = LogFactory.getLog(HttpFileServerHandler.class); @Override public void channelRead0(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception { if (request.getMethod() != HttpMethod.GET) { sendError(ctx, HttpResponseStatus.METHOD_NOT_ALLOWED); return; } final String path = sanitizeUri(request.getUri()); if (path == null) { sendError(ctx, HttpResponseStatus.FORBIDDEN); return; } File file = new File(path); if (file.isHidden() || !file.exists()) { sendError(ctx, HttpResponseStatus.NOT_FOUND); return; } if (!file.isFile()) { sendError(ctx, HttpResponseStatus.FORBIDDEN); return; } RandomAccessFile raf; try { raf = new RandomAccessFile(file, "r"); } catch (FileNotFoundException fnfe) { sendError(ctx, HttpResponseStatus.NOT_FOUND); return; } long fileLength = raf.length(); HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK); HttpHeaders.setContentLength(response, fileLength); setContentTypeHeader(response); // Write the initial line and the header. ctx.write(response); // Write the content. ChannelFuture writeFuture; ChannelFuture lastContentFuture; if (ctx.pipeline().get(SslHandler.class) != null) { // Cannot use zero-copy with HTTPS. lastContentFuture = ctx.writeAndFlush(new HttpChunkedInput(new ChunkedFile(raf, 0, fileLength, 8192))); } else { // No encryption - use zero-copy. final FileRegion region = new DefaultFileRegion(raf.getChannel(), 0, fileLength); writeFuture = ctx.write(region); lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT); writeFuture.addListener(new ChannelProgressiveFutureListener() { @Override public void operationProgressed(ChannelProgressiveFuture future, long progress, long total) throws Exception { LOG.trace(String.format("%s: %d / %d", path, progress, total)); } @Override public void operationComplete(ChannelProgressiveFuture future) throws Exception { region.release(); } }); } // 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) throws Exception { Channel ch = ctx.channel(); if (cause instanceof TooLongFrameException) { sendError(ctx, HttpResponseStatus.BAD_REQUEST); return; } LOG.error(cause.getMessage(), cause); if (ch.isActive()) { sendError(ctx, HttpResponseStatus.INTERNAL_SERVER_ERROR); } } private static String sanitizeUri(String uri) { // Decode the path. try { uri = URLDecoder.decode(uri, "UTF-8"); } catch (UnsupportedEncodingException e) { try { uri = URLDecoder.decode(uri, "ISO-8859-1"); } catch (UnsupportedEncodingException e1) { throw new Error(); } } // 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.startsWith(".") || uri.endsWith(".")) { return null; } return uri; } private static void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) { FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, status, Unpooled.copiedBuffer("Failure: " + status.toString() + "\r\n", CharsetUtil.UTF_8)); response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/plain; charset=UTF-8"); // Close the connection as soon as the error message is sent. ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE); } /** * Sets the content type header for the HTTP Response * * @param response * HTTP response */ private static void setContentTypeHeader(HttpResponse response) { response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/plain; charset=UTF-8"); } }