CODEWITHSUNDEEP
javajarversionpatch
PulsePanda
PulsePanda

Reputation: 1856

Self updating game in java

I'm making a game, in Java, that has these following important features:

1) Connects to a remote Server (which i made), and will check for updates and install them if necessary 2) is NOT A SINGLE .JAR FILE (ie. has multiple .jar's and other things, such as .png, .wav, etc) 3) JAVA WEB START IS NOT AN OPTION, AS I WANT TO MAKE THIS ALL MYSELF

keeping the things above in mind, i have run into a problem. i have no clue how to implement a multiple "patch" update system. currently i have 1 .txt file, that the server reads from, and sends the files listed in the .txt to the client, which then moves them into place. The problem is, that is only useful for maybe 2 updates. I'm looking for a more useful, long term solution, and i need some help. here are some of the things i've thought of:

1) have a zip folder named after each version (problem: how would the client get ALL of the most updated files 2) have a .txt file INSIDE of each jar containing the version (problem: cant do that with png's or wav's, and i dont know how i would read the txt file to begin with)

i really need some help, i've tried googling it, i've thought about it for going on 3 weeks now, and cannot think of anything.

QUESTION: how would i make a game/program update with multiple patches?

Upvotes: 0

Views: 282

Answers (2)

Stephen C
Stephen C

Reputation: 718876

Firstly, the best solution by a long, long way is to use Webstart / JNLP.

But if you insist on not using it (for whatever reason then) then it is technically possible. However:

  • It is messy and complicated.

  • It will either be very inefficient ('cos you have to load the entire program each time the user), or the user has to trust you enough to install your program with permissions that will allow it to install random stuff on his machine without notice.

The way to do it is to split the game into a launcher part and an application part. The launcher needs permissions to write and delete (non-temporary) files, and fetch stuff from the internet. It "calls home" to find out the latest version(s) of the application files, and then downloads and installs them. It has to cope with all sorts of error conditions, and it needs to make sure that nothing can trick it into installing bad stuff on the user's machine, etcetera, is someone spoofs your update service.

Of course, JNLP takes care of all of this, and lots more besides. People are going to be more willing to install the JNLP infrastructure that yours ... which might be insecure, or actively nasty (for all they know). (I for one wouldn't install a self updating application on my machine unless it was supplied by a company with impeccable credentials.)

Upvotes: 1

Maxim Shoustin
Maxim Shoustin

Reputation: 77904

I think you need here JNLP framework.

JNLP provides followed things:

  • allows to user to download jars from server
  • on launch verifies if application need to update
  • runs on local JVM

Actually, every java application you can convert to JNLP. Just to sign on all jars that your game contains, create executable jar from your game and create single Web page from where you can download your game

Upvotes: 0

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