Force refresh of client's java cache.

Question

I have an Oracle Application server that has been upgraded. It serves users a java file which they launch in their browser. After the upgrade user's browsers are still pulling the old java file from their local cache and receiving an error. If a user clears their java cache things will work correctly.

There has got to be a way to tell clients that they need to get the new java file rather then using their local cached version.

Answer 1

The algorithm for Java applet caching is described here.

Try getting Apache to return reasonable Last-Modified headers. If this is not happening, this could mess up the caching algorithm. Last-Modified should be a later date than the previous applet.

Also check that the MIME type for the JAR files from Apache are application/java-archive, as not having this can mess up caching (but usually this prevents them from being cached).

There is also the option of making changes to the HTML files as described.

Answer 2

Are you able to change the link that users click to open the java file? If so, there are a couple of ways to fix it there:

• change appname.jar to appname.jar?version=20120124.
• add <param name="cache_option" value="no"> between <object> and </object>. (This will cause clients to reload the latest version every time, not just once.)