This very simple guess game does not work

I try to make a very simple guess game and i wanted to add an exciting addition by doing an analysis of the guesswork from the user using switch function but I was surprised that it did not run that analysis

public static void main (String args[]){

Scanner reader = new Scanner(System.in).useLocale(Locale.ROOT);

int num = 8 , guess;
boolean positiveguess = true;
while (positiveguess) {
System.out.println("Enter your guess = ");
guess = reader.nextInt();
if (guess != num)
    switch(guess)
    {
        case '1':
            if (num-5 < guess && num + 5 >guess)
                System.out.println("Your guess is almost close! \nTry again ");
       break;
        case '2':
            if (num-10 < guess && num + 10 >guess)
                System.out.println("You need to guess again ");
        break;    
    }              
else
    positiveguess = false;
    
}
System.out.println("Great !");

Your switch is based on the user input and not the difference between given and exepcted value. First I suggest you to keep it simple with if/else structure like

public class Main {

    public static void main (String args[]) {

        Scanner reader = new Scanner(System.in).useLocale(Locale.ROOT);

        int num = 8, guess;
        boolean positiveguess = true;
        while (positiveguess) {
            System.out.println("Enter your guess = ");
            guess = reader.nextInt();
            if (guess != num) {
                if (num - 5 < guess && num + 5 > guess) {
                    System.out.println("Your guess is almost close! \nTry again ");
                } else if (num - 10 < guess && num + 10 > guess) {
                    System.out.println("You need to guess again ");
                }
            } else {
                positiveguess = false;
            }
        }
        System.out.println("Great !");
    }
}

Then I suggest you to remove your positiveguess and do a while loop with your condition inside. And use Math.abs() to get the difference between the guess and the expected value.

public class Main {

    public static void main (String args[]) {

        Scanner reader = new Scanner(System.in).useLocale(Locale.ROOT);

        int num = 8;
        int guess = Integer.MIN_VALUE;

        while (guess != num) {
            System.out.println("Enter your guess = ");
            guess = reader.nextInt();

            int diff = Math.abs(num - guess);
            if (diff != 0) {
                if (diff < 5) {
                    System.out.println("Your guess is almost close! \nTry again ");
                } else if (diff < 10) {
                    System.out.println("You need to guess again ");
                } else {
                    System.out.println("You're way too far bro");
                }
            }
        }
        System.out.println("Great !");
    }
}

You are using switch wrongly here. It seems you are looking for something like this:

switch (guess) {
    // first case
    case (num-5 < guess && num + 5 >guess):
        System.out.println("Your guess is almost close! \nTry again ");
    // second case
    case (num-10 < guess && num + 10 >guess):
        System.out.println("You need to guess again ");
}

But this is not valid syntax. In Java, a switch/case can only compare elements to other elements of the same type (or, in newer version, multiple elements, or a class), not perform complex conditional checks like if can.
Probably you then tried to "fix" it by combining case '1' and the if statements, but while legal, case '1' will only be the case if guess is '1' (i.e. 49), and only then will continue to check the if condition.

Instead, just drop the switch/case and use your if statements directly (don't forget the else):

if (num-5 < guess && num+5 > guess) {
    System.out.println("Your guess is almost close! \nTry again ");
} else if (num-10 < guess && num+10 > guess) {
    System.out.println("You need to guess again ");
}

Also, you could make those checks more readable by changing the order to (num-5 < guess && guess < num+5) or using Math.abs to find the absolute difference and use that in the condition.