giacomo 01/01/13 05:39:19
Modified: src/org/apache/cocoon/reading Tag: xml-cocoon2
ResourceReader.java
Log:
The ResourceReader conforms now much more to the HTTP protocol concerning the
caching headers like if-modified-since. This will increase performance of this
Component
Revision Changes Path
No revision
No revision
1.1.2.11 +34 -9
xml-cocoon/src/org/apache/cocoon/reading/Attic/ResourceReader.java
Index: ResourceReader.java
===================================================================
RCS file:
/home/cvs/xml-cocoon/src/org/apache/cocoon/reading/Attic/ResourceReader.java,v
retrieving revision 1.1.2.10
retrieving revision 1.1.2.11
diff -u -r1.1.2.10 -r1.1.2.11
--- ResourceReader.java 2001/01/12 09:53:09 1.1.2.10
+++ ResourceReader.java 2001/01/13 13:39:19 1.1.2.11
@@ -15,9 +15,11 @@
import java.net.URL;
import java.net.MalformedURLException;
import java.net.URLConnection;
+import java.util.Enumeration;
import java.util.Hashtable;
import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpServletRequest;
import javax.servlet.ServletContext;
import org.apache.cocoon.Cocoon;
@@ -28,17 +30,19 @@
/**
*
* @author <a href="mailto:[EMAIL PROTECTED]">Giacomo Pati</a>
- * @version CVS $Revision: 1.1.2.10 $ $Date: 2001/01/12 09:53:09 $
+ * @version CVS $Revision: 1.1.2.11 $ $Date: 2001/01/13 13:39:19 $
*
* The <code>ResourceReader</code> component is used to serve binary data
- * in a sitemap pipeline.
+ * in a sitemap pipeline. It makes use of HTTP Headers to determine if
+ * the requested resource should be written to the <code>OutputStream</code>
+ * or if it can signal that it hasn't changed.
*
* Parameters:
* <dl>
* <dt><expires></dt>
* <dd>This parameter is optional. When specified it determines how
long
- * in miliseconds the resources can be cached by any proxy between
- * Cocoon2 and the requesting browser.
+ * in miliseconds the resources can be cached by any proxy or
browser
+ * between Cocoon2 and the requesting visitor.
* </dd>
* </dl>
*/
@@ -48,32 +52,40 @@
* Generates the requested resource.
*/
public void generate() throws IOException, ProcessingException {
+ HttpServletRequest req = (HttpServletRequest)
objectModel.get(Cocoon.REQUEST_OBJECT);
HttpServletResponse res = (HttpServletResponse)
objectModel.get(Cocoon.RESPONSE_OBJECT);
+
if (res == null) {
throw new ProcessingException ("Missing a Response object in the
objectModel");
}
+ if (req == null) {
+ throw new ProcessingException ("Missing a Request object in the
objectModel");
+ }
String src = null;
File file = null;
URL url = null;
URLConnection conn = null;
InputStream is = null;
long len = 0;
- long lastModified = 0;
try {
- if(this.source.indexOf(":/")!=-1) {
+ if(this.source.indexOf(":/") != -1) {
src = this.source;
url = new URL (src);
conn = url.openConnection();
+ if (!modified (conn.getLastModified(), req, res)) {
+ return;
+ }
len = conn.getContentLength();
is = conn.getInputStream();
- lastModified = conn.getLastModified();
} else {
src = this.resolver.resolveEntity
(null,this.source).getSystemId();
url = new URL (src);
file = new File (url.getFile());
+ if (!modified (file.lastModified(), req, res)) {
+ return;
+ }
len = file.length();
is = new FileInputStream (file);
- lastModified = file.lastModified();
}
} catch (SAXException se) {
log.error("ResourceReader: error resolving source \"" + source +
"\"", se);
@@ -88,7 +100,6 @@
is.read(buffer);
is.close();
res.setContentLength(buffer.length);
- res.setDateHeader("Last-Modified", lastModified);
long expires = parameters.getParameterAsInteger("expires", -1);
if (expires > 0) {
res.setDateHeader("Expires", System.currentTimeMillis()+expires);
@@ -96,6 +107,20 @@
res.setHeader("Accept-Ranges", "bytes");
out.write ( buffer );
}
+
+ /**
+ * Checks if the file has been modified
+ */
+ private boolean modified (long lastModified, HttpServletRequest req,
HttpServletResponse res) {
+ res.setDateHeader("Last-Modified", lastModified);
+ long if_modified_since = req.getDateHeader("if-modified-since");
+ if (if_modified_since >= lastModified) {
+ res.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
+ }
+ log.debug("ResourceReader: resource has " + ((if_modified_since <
lastModified) ? "" : "not ") + "been modified");
+ return (if_modified_since < lastModified);
+ }
+
/**
* Returns the mime-type of the resource in process.
*/
