/*
* 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 org.jboss.netty.example.http.file;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelFutureProgressListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.DefaultFileRegion;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.FileRegion;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.frame.TooLongFrameException;
import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
import org.jboss.netty.handler.codec.http.HttpRequest;
import org.jboss.netty.handler.codec.http.HttpResponse;
import org.jboss.netty.handler.codec.http.HttpResponseStatus;
import org.jboss.netty.handler.ssl.SslHandler;
import org.jboss.netty.handler.stream.ChunkedFile;
import org.jboss.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.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;
import static org.jboss.netty.handler.codec.http.HttpHeaders.Names.*;
import static org.jboss.netty.handler.codec.http.HttpHeaders.*;
import static org.jboss.netty.handler.codec.http.HttpMethod.*;
import static org.jboss.netty.handler.codec.http.HttpResponseStatus.*;
import static org.jboss.netty.handler.codec.http.HttpVersion.*;
/**
* 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>.
*
* <h3>How Browser Caching Works</h3>
*
* 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>
*
* <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 SimpleChannelUpstreamHandler {
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;
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
HttpRequest request = (HttpRequest) e.getMessage();
if (request.getMethod() != GET) {
sendError(ctx, METHOD_NOT_ALLOWED);
return;
}
final String path = sanitizeUri(request.getUri());
if (path == null) {
sendError(ctx, FORBIDDEN);
return;
}
File file = new File(path);
if (file.isHidden() || !file.exists()) {
sendError(ctx, NOT_FOUND);
return;
}
if (!file.isFile()) {
sendError(ctx, FORBIDDEN);
return;
}
// Cache Validation
String ifModifiedSince = request.getHeader(IF_MODIFIED_SINCE);
if (ifModifiedSince != null && ifModifiedSince.length() != 0) {
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 fnfe) {
sendError(ctx, NOT_FOUND);
return;
}
long fileLength = raf.length();
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
setContentLength(response, fileLength);
setContentTypeHeader(response, file);
setDateAndCacheHeaders(response, file);
Channel ch = e.getChannel();
// Write the initial line and the header.
ch.write(response);
// Write the content.
ChannelFuture writeFuture;
if (ch.getPipeline().get(SslHandler.class) != null) {
// Cannot use zero-copy with HTTPS.
writeFuture = ch.write(new ChunkedFile(raf, 0, fileLength, 8192));
} else {
// No encryption - use zero-copy.
final FileRegion region =
new DefaultFileRegion(raf.getChannel(), 0, fileLength);
writeFuture = ch.write(region);
writeFuture.addListener(new ChannelFutureProgressListener() {
public void operationComplete(ChannelFuture future) {
region.releaseExternalResources();
}
public void operationProgressed(
ChannelFuture future, long amount, long current, long total) {
System.out.printf("%s: %d / %d (+%d)%n", path, current, total, amount);
}
});
}
// Decide whether to close the connection or not.
if (!isKeepAlive(request)) {
// Close the connection when the whole content is written out.
writeFuture.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
throws Exception {
Channel ch = e.getChannel();
Throwable cause = e.getCause();
if (cause instanceof TooLongFrameException) {
sendError(ctx, BAD_REQUEST);
return;
}
cause.printStackTrace();
if (ch.isConnected()) {
sendError(ctx, 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;
}
// Convert to absolute path.
return System.getProperty("user.dir") + File.separator + uri;
}
private static void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, status);
response.setHeader(CONTENT_TYPE, "text/plain; charset=UTF-8");
response.setContent(ChannelBuffers.copiedBuffer(
"Failure: " + status.toString() + "\r\n",
CharsetUtil.UTF_8));
// Close the connection as soon as the error message is sent.
ctx.getChannel().write(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) {
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, NOT_MODIFIED);
setDateHeader(response);
// Close the connection as soon as the error message is sent.
ctx.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
}
/**
* Sets the Date header for the HTTP response
*
* @param response
* HTTP response
*/
private static void setDateHeader(HttpResponse response) {
SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US);
dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE));
Calendar time = new GregorianCalendar();
response.setHeader(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.setHeader(DATE, dateFormatter.format(time.getTime()));
// Add cache headers
time.add(Calendar.SECOND, HTTP_CACHE_SECONDS);
response.setHeader(EXPIRES, dateFormatter.format(time.getTime()));
response.setHeader(CACHE_CONTROL, "private, max-age=" + HTTP_CACHE_SECONDS);
response.setHeader(
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.setHeader(CONTENT_TYPE, mimeTypesMap.getContentType(file.getPath()));
}
}