Showing posts with label Applet. Show all posts
Showing posts with label Applet. Show all posts

Thursday, November 29, 2007

3 easy steps to self-sign a Applet Jar file

Found this link that explains how to self-sign an applet in 3 easy steps:

1. keytool -genkey -keystore myKeyStore -alias me

2. keytool -selfcert -keystore myKeyStore -alias me

3. jarsigner -keystore myKeyStore jarfile.jar me

Thats it..simple and sweet :)

Tuesday, July 24, 2007

Java Applet Caching Issues

I spent the last 3 days in frustration trying to get Java Plug-in cache mechanisms to work.
Since JDK 1.5, the Java Plug-in has advanced caching options using the "cache_archive" and
"cache_version" tags.

One particular vexing issue that I faced was that inspite of adding all the cache directives in the applet's object tag, the jar files were not cached. A quick google showed 2 bugs:
1. Unfortunately, if the servers do not return Last-Modified or Expires in HTTP response headers, it would disable plugin caching for the connection, and plugin would try to redownload the file again without caching. This results in two HTTP GET requests per file.
2. If a running applet makes a call to URLConnection.setDefaultUseCaches(false), then all subsequent loads from this plugin will exhibit the multiple-load-request behaviour.

In our case, the Applet was setting the cache as false in the code. Hence the cache directives were not working as expected. More information on this can be found here and here.