Question

This is my Config File(Test.txt)

CommandA   75%
CommandB   15%
CommandC   10%

I wrote a multithreading program in which I am reading the files line by line but not sure how should I do the above question in which this much percentage(75%) of random calls go to CommandA, and this much percentage(15%) of random calls go to CommandB and same with CommandC.

public static void main(String[] args) {

            for (int i = 1; i <= threadSize; i++) {
                new Thread(new ThreadTask(i)).start();
            }
        }

class ThreadTask implements Runnable {

        public synchronized void run() {
            BufferedReader br = null;

            try {
                String line;

                br = new BufferedReader(new FileReader("C:\\Test.txt"));

                while ((line = br.readLine()) != null) {
                    String[] s = line.split("\\s+");
                    for (String split : s) {
                    System.out.println(split);
                }
            }

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (br != null)br.close();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }

        }
    }

Answer 1

Get a random number 1-100. If the number is 1-75 do command A, 76-90 do command B, 91-100 do command C.

EDITED for comment:

There are two ways I would consider doing this. If you only have the three commands (A, B, C) then you can do a simple:

    int[] commandPercentages = {75, 15, 10};        
    int randomNumber = 90;

    if((randomNumber -= commandPercentages[0]) < 0) {
        //Execute Command A
    }
    else if((randomNumber -= commandPercentages[1]) < 0) {
        //Execute Command B
    }
    else {
        //Execute Command C
    }

if you have a lot of complicated commands you can set up the commands like so:

private abstract class Command {
    int m_percentage;       
    Command(int percentage) {
        m_percentage = percentage;
    }       
    int getPercentage() {
        return m_percentage;
    }
    abstract void executeCommand();
};

private class CommandA extends Command {        
    CommandA(int percentage) {
        super(percentage);
    }
    @Override
    public void executeCommand() {
        //Execute Command A
    }       
}

private class CommandB extends Command {        
    CommandB(int percentage) {
        super(percentage);
    }
    @Override
    public void executeCommand() {
        //Execute Command B
    }

}

and then choose the command like so:

    Command[] commands = null;  
    int randomNumber = 90;

    commands[0] = new CommandA(75);
    commands[1] = new CommandB(25);

    for(Command c: commands) {
        randomNumber -= c.getPercentage();
        if(randomNumber < 0) {
            c.executeCommand();
        }
    }