/**
* Copyright 2012 Ronen Hamias, Anton Kharenko
*
* 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.scalecube.socketio.pipeline;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpUtil;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.handler.codec.http.QueryStringDecoder;
import io.netty.handler.stream.ChunkedStream;
import io.netty.handler.stream.ChunkedWriteHandler;
import io.netty.util.CharsetUtil;
import io.netty.util.ReferenceCountUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.activation.MimetypesFileTypeMap;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.TimeZone;
@ChannelHandler.Sharable
public class ResourceHandler extends ChannelInboundHandlerAdapter {
private final Logger log = LoggerFactory.getLogger(getClass());
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 final Map<String, URL> resources = new HashMap<>();
public void addResource(String pathPart, String resourcePath) {
URL resUrl = getClass().getResource(resourcePath);
if (resUrl == null) {
log.error("The specified resource was not found: " + resourcePath);
return;
}
resources.put(pathPart, resUrl);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof HttpRequest) {
HttpRequest req = (HttpRequest) msg;
QueryStringDecoder queryDecoder = new QueryStringDecoder(req.uri());
String requestPath = queryDecoder.path();
URL resUrl = resources.get(requestPath);
if (resUrl != null) {
if (log.isDebugEnabled())
log.debug("Received HTTP resource request: {} {} from channel: {}", req.method(), requestPath, ctx.channel());
URLConnection fileUrl = resUrl.openConnection();
long lastModified = fileUrl.getLastModified();
// check if file has been modified since last request
if (isNotModified(req, lastModified)) {
sendNotModified(ctx);
return;
}
// create resource input-stream and check existence
final InputStream is = fileUrl.getInputStream();
if (is == null) {
sendError(ctx, HttpResponseStatus.NOT_FOUND);
return;
}
// create ok response
HttpResponse res = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
// set Content-Length header
HttpUtil.setContentLength(res, fileUrl.getContentLengthLong());
// set Content-Type header
setContentTypeHeader(res, fileUrl);
// set Date, Expires, Cache-Control and Last-Modified headers
setDateAndCacheHeaders(res, lastModified);
// write initial response header
ctx.write(res);
// write the content stream
ctx.pipeline().addBefore(ctx.name(), "chunked-writer-handler", new ChunkedWriteHandler());
ChannelFuture writeFuture = ctx.writeAndFlush(new ChunkedStream(is, fileUrl.getContentLength()));
// add operation complete listener so we can close the channel and the input stream
writeFuture.addListener(ChannelFutureListener.CLOSE);
ReferenceCountUtil.release(msg);
return;
}
}
super.channelRead(ctx, msg);
}
/*
* Checks if the content has been modified sicne the date provided by the IF_MODIFIED_SINCE http header
* */
private boolean isNotModified(HttpRequest request, long lastModified) throws ParseException {
String ifModifiedSince = request.headers().get(HttpHeaderNames.IF_MODIFIED_SINCE);
if (ifModifiedSince != null && !ifModifiedSince.equals("")) {
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 = lastModified / 1000;
return ifModifiedSinceDateSeconds == fileLastModifiedSeconds;
}
return false;
}
/*
* Sends a Not Modified response to the client
*
* */
private void sendNotModified(ChannelHandlerContext ctx) {
HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.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 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.headers().set(HttpHeaderNames.DATE, dateFormatter.format(time.getTime()));
}
/**
* Sends an Error response with status message
*
* @param ctx channel context
* @param status status
*/
private void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, status);
response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=UTF-8");
ByteBuf content = Unpooled.copiedBuffer("Failure: " + status.toString() + "\r\n", CharsetUtil.UTF_8);
ctx.write(response);
// Close the connection as soon as the error message is sent.
ctx.writeAndFlush(content).addListener(ChannelFutureListener.CLOSE);
}
/**
* Sets the Date and Cache headers for the HTTP Response
*
* @param response
* HTTP response
*/
private void setDateAndCacheHeaders(HttpResponse response, long lastModified) {
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(HttpHeaderNames.DATE, dateFormatter.format(time.getTime()));
// Add cache headers
time.add(Calendar.SECOND, HTTP_CACHE_SECONDS);
response.headers().set(HttpHeaderNames.EXPIRES, dateFormatter.format(time.getTime()));
response.headers().set(HttpHeaderNames.CACHE_CONTROL, "private, max-age=" + HTTP_CACHE_SECONDS);
response.headers().set(HttpHeaderNames.LAST_MODIFIED, dateFormatter.format(new Date(lastModified)));
}
/**
* Sets the content type header for the HTTP Response
*
* @param response
* HTTP response
*/
private void setContentTypeHeader(HttpResponse response, URLConnection resUrlConnection) {
MimetypesFileTypeMap mimeTypesMap = new MimetypesFileTypeMap();
String resName = resUrlConnection.getURL().getFile();
response.headers().set(HttpHeaderNames.CONTENT_TYPE, mimeTypesMap.getContentType(resName));
}
}
