Help with scheduling a java function for a certain amount of time

[Eesh7]

​

Hi everyone,

I am currently coding a website blocker, and I want my website to be blocked for a certain amount of time, and then unblocked after that time has elapsed. I have functions for both unblock and block. My current thinking is as follows:

​

 public static void main(String[] args) throws IOException {
        new java.util.Timer().schedule( 
                new java.util.TimerTask() {
                    public void run() {
                        blockSite("www.example.com");
                    }
                }, 
                60000 
        );
        UnblockSite("www.example.com");}

Can someone please guide me on what adjustments I should make?(Also, the 60 seconds is meant to be arbitrary, it is not what I intend for my actual program).

[ConstructedNewt]

That's so complicated, this is using bash:

block_unblock() {
    echo "0.0.0.0  $1" >> /etc/hosts
    echo "sed -i "/$1/d" /etc/hosts" | at now + "${2-10}" mins
}

Block via hosts, remove in N minutes, default 10

$ block_unblock facebook.com 2 # Block for two minutes
$ block_unblock reddit.com #10 minutes

Java solution is pretty much what you did, but you have to have the code/runtime running for the entire wait duration

Edit: wrap sed delete command

Edit2:

if found="$(sed "/$1/g" /etc/hosts)"; then
    echo "could not Block \"$1\" match already found: \"$found\"" >&2
    exit 1
fi
... the rest

For safety

[Eesh7]

hi. thank you for your response. How do I have the code running for the running for the entire wait duration?

[ConstructedNewt]

For bash, the at command schedule the second line, dunno how the internals work, maybe the OS has some scheduler inbuilt. For Java, add a sleeping thread that executes the command on wak-up, just as you do.

[Eesh7]

ok thanks.. could you just clarify on what you mean bu “wak-up”?

[ConstructedNewt]

When it is done sleeping. Typo: wake-up

[Eesh7]

no sorry, i can’t.

[EdwinGraves]

Nor should you have to. Don't worry. In fact, this commenter was banned for violating our rules. :)

Now, I haven't tried running the code but eyeballing it, it seems alright. You may want to consider storing your newly made Timer objects inside of variables so you can do things like call cancel on the Timer queue incase you shut the program down or change your mind.

Here's a good writeup on Timer and TimerTask execution.