Halo, I got another problem, and try to get comment from you all, so decide which method is better. Now i need to copy some JAR file into the EXT directory before i run the applet.... i want the applet check the client side see whether got the require JAR file is inside the ext directory, if exist then return else the applet will download the JAR file from server and put inside the EXT directory and return... so got any idea how to do this..? Another Question is after i copy the require JAR into EXT library, do i need to restart PC so that installation that effect? Thanks for comment.=)
Applets don't work that way. But there's something better. When you reference a web page containing an applet, the browser will download the applet the first time. Thereafter a copy is cached on the client machine and no further downloads need be done. It's not quite that simple, since the browser determines whether or not to use a cached copy and how long a copy will remain in cache, but the important thing is that you don't have to write your own caching mechanism. And, in fact, you'd find it very difficult to do so, since the kind of behaviour you're describing is a lot like how viruses and malware install themselves, and Java is designed to prevent such activities. Unlike Applets, Java Applications can be installed manually. However it's more convenient to make the Application available via Java WebStart, which will automatically install the Application and will check for updates as needed.
"privilege" comes from the Latin words for "private" and "law" (legal) and dates to feudal times. To "claim privilege" meant that you were above the laws that applied to the common people.
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