From a85249ced80fc3b556e5e54ed0f84d639786c1f2 Mon Sep 17 00:00:00 2001 From: Veebs Date: Sat, 5 Mar 2011 15:40:34 +1100 Subject: [PATCH] Added handing of HTTP headers with respect to browser caching and cache validation. --- .../file/HttpStaticFileServerHandler.java | 133 +++++++++++++++++- 1 file changed, 132 insertions(+), 1 deletion(-) diff --git a/src/main/java/org/jboss/netty/example/http/file/HttpStaticFileServerHandler.java b/src/main/java/org/jboss/netty/example/http/file/HttpStaticFileServerHandler.java index 6ac22fb395..b06350b38d 100644 --- a/src/main/java/org/jboss/netty/example/http/file/HttpStaticFileServerHandler.java +++ b/src/main/java/org/jboss/netty/example/http/file/HttpStaticFileServerHandler.java @@ -26,6 +26,13 @@ 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.TimeZone; + +import javax.activation.MimetypesFileTypeMap; import org.jboss.netty.buffer.ChannelBuffers; import org.jboss.netty.channel.Channel; @@ -40,6 +47,7 @@ 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.HttpHeaders; import org.jboss.netty.handler.codec.http.HttpRequest; import org.jboss.netty.handler.codec.http.HttpResponse; import org.jboss.netty.handler.codec.http.HttpResponseStatus; @@ -48,11 +56,50 @@ import org.jboss.netty.handler.stream.ChunkedFile; import org.jboss.netty.util.CharsetUtil; /** + * Web browser caching works with HTTP headers as illustrated by the following sample. + * + * + * 
+ * 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
+ * 
+ *
+ * * @author The Netty Project * @author Trustin Lee */ 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(); @@ -77,6 +124,19 @@ public class HttpStaticFileServerHandler extends SimpleChannelUpstreamHandler { return; } + // Cache Validation + String ifModifiedSince = request.getHeader(HttpHeaders.Names.IF_MODIFIED_SINCE); + if (ifModifiedSince != null && !ifModifiedSince.equals("")) + { + SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT); + Date ifModifiedSinceDate = dateFormatter.parse(ifModifiedSince); + if (ifModifiedSinceDate.getTime() == file.lastModified()) + { + sendNotModified(ctx); + return; + } + } + RandomAccessFile raf; try { raf = new RandomAccessFile(file, "r"); @@ -88,7 +148,9 @@ public class HttpStaticFileServerHandler extends SimpleChannelUpstreamHandler { 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. @@ -178,4 +240,73 @@ public class HttpStaticFileServerHandler extends SimpleChannelUpstreamHandler { // 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 void sendNotModified(ChannelHandlerContext ctx) { + HttpResponse response = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.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 + * @param file + * file to extract content type + */ + private void setDateHeader(HttpResponse response) { + SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT); + dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE)); + + Calendar time = new GregorianCalendar(); + response.setHeader(HttpHeaders.Names.DATE, dateFormatter.format(time.getTime())); + } + + /** + * Sets the Date and Cache headers for the HTTP Response + * + * @param response + * HTTP response + * @param file + * file to extract content type + */ + private void setDateAndCacheHeaders(HttpResponse response, File filetoCache) { + SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT); + dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE)); + + // Date header + Calendar time = new GregorianCalendar(); + response.setHeader(HttpHeaders.Names.DATE, dateFormatter.format(time.getTime())); + + // Add cache headers + time.add(Calendar.SECOND, HTTP_CACHE_SECONDS); + response.setHeader(HttpHeaders.Names.EXPIRES, dateFormatter.format(time.getTime())); + + response.setHeader(HttpHeaders.Names.CACHE_CONTROL, "private, max-age=" + HTTP_CACHE_SECONDS); + + response.setHeader(HttpHeaders.Names.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 void setContentTypeHeader(HttpResponse response, File file) { + MimetypesFileTypeMap mimeTypesMap = new MimetypesFileTypeMap(); + response.setHeader(HttpHeaders.Names.CONTENT_TYPE, mimeTypesMap.getContentType(file.getPath())); + } + }