ScheduledExecutorService

[merry carbon]

// Try-resource
        try (ScheduledExecutorService exec = Executors.newSingleThreadScheduledExecutor()){
            exec.scheduleAtFixedRate(new Runnable() {
                                         @Override
                                         public void run() {
                                                System.out.println("running");
                                         }
                                     }
                    , 0, 1, TimeUnit.SECONDS);
        }

I have this ScheduledExecutorService, but I'm not sure how I can tell if it's working as I don't see anything printed in my terminal. I assume because it's running on another thread it's printing elsewhere?

[finite bloom]

Detected code, here are some useful tools:

Formatted code

// Try-resource
try (ScheduledExecutorService exec = Executors.newSingleThreadScheduledExecutor()) {
  exec.scheduleAtFixedRate(new Runnable() {
    @Override
    public void run() {
      System.out.println("running");
    }
  }
  , 0, 1, TimeUnit.SECONDS);
}

<@&987246399047479336> please have a look, thanks.

[finite bloom]

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@Override
public void run() {
// code to be executed repeatedly
}
}, initialDelay, period, TimeUnit.SECONDS);
} catch (Exception e) {
e.printStackTrace();
}

The `ScheduledExecutorService` is a class in the `java.util.concurrent` package that provides methods for scheduling tasks to be executed at fixed intervals or after a delay. In this example, we are using the `newSingleThreadScheduledExecutor()` method from the `Executors` class to create a single-threaded executor service.

Inside the try-with-resources block, we call the `scheduleAtFixedRate()` method on the executor service. This method takes four parameters:
1. A `Runnable` object that defines the task to be executed repeatedly.
2. The initial delay before the first execution of the task.
3. The period between successive executions of the task.
4. The time unit for specifying the initial delay and period.

In this example, we are using an anonymous inner class to define the `Runnable` object. Inside the `run()` method of this object, we can write our code that needs to be executed repeatedly.

If any exception occurs during the execution of the scheduled task, it will be caught by the catch block and printed using `e.printStackTrace()`.

[soft temple]

System.out is always the same, it doesn't change per thread

meaning it's not running

[merry carbon]

ah good to know, thanks

do you see anything that may explain why it's not running in that codeblock?

[tidal crown]

the code seems fine for me, might need to supply more context

[merry carbon]

May I supply my main?

public class Main {
    public static void main(String[] args) throws LoginException {

        // Load the .env file
        File file = new File(".env");
        String absolutePath = file.getAbsolutePath();

        // Get the absolute path of the .env file using the current working directory
        Dotenv config = Dotenv.configure().directory(absolutePath).filename(".env").load();
        String token = config.get("TOKEN");

        // Create a database connection
        DB db;

        MyBot bot;
        try {
            db = new DB("scheduledServers.db");
            bot = new MyBot(token, db);
        }
        catch (LoginException e) {
            throw new LoginException(e.getMessage());
        }

        // Try-resource
        try (ScheduledExecutorService exec = Executors.newSingleThreadScheduledExecutor()){
            exec.scheduleAtFixedRate(new Runnable() {
                                         @Override
                                         public void run() {
                                                System.out.println("running");
                                         }
                                     }
                    , 0, 1, TimeUnit.SECONDS);
        }
    }
}

[finite bloom]

Detected code, here are some useful tools:

Formatted code

public class Main {
  public static void main(String[] args) throws LoginException {
    // Load the .env file
    File file = new File(".env");
    String absolutePath = file.getAbsolutePath();
    // Get the absolute path of the .env file using the current working directory
    Dotenv config = Dotenv.configure().directory(absolutePath).filename(".env").load();
    String token = config.get("TOKEN");
    // Create a database connection
    DB db;
    MyBot bot;
    try {
      db = new DB("scheduledServers.db");
      bot = new MyBot(token, db);
    } catch (LoginException e) {
      throw new LoginException(e.getMessage());
    }
    // Try-resource
    try (ScheduledExecutorService exec = Executors.newSingleThreadScheduledExecutor()) {
      exec.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
          System.out.println("running");
        }
      }
      , 0, 1, TimeUnit.SECONDS);
    }
  }
}

[soft temple]

Wait, doesn't the try with resources just destroy the exec instance

before the runnable is run

that's what try with resources does

it doesn't wait

[tidal crown]

yeah true

[merry carbon]

ohh would it close it instantly

[soft temple]

yes

[merry carbon]

ahhhh alright that makes alot of sense lol

[tidal crown]

you would need to add join one the future and check if its working

[soft temple]

Or don't use a try with resources and store it as a instance variable somewhere

and close manually

[tidal crown]

or what the method is called

not sure rn

[merry carbon]

yea I'll give this one a try

[tidal crown]

actually the default get will wait

[soft temple]

yuh

[merry carbon]

might be a funny question, but when would it make sense the close it?

if I shut it down at the end of my main it just basically never runs

I could put it in like an infinite while loop lol

[uneven flame]

Don't shut it down

[tidal crown]

when the application should shutdown or the fucntionality is not used anymore

[merry carbon]

this doesn't cause any resource leaks or anything? (mb not too familiar with memory leaks and stuff)

acc I always need it

so ig there's no point in freeing the resources

[uneven flame]

It will exist until your app stops

[merry carbon]

you're right, that's what I want. Thanks all 🙂

[tidal crown]

but I think thats a non-deamon thread

so you need to close all tasks running currently

or otherwise the jvm will stay alive

until those finished