Primality test Java

It is a code for primality test. If you have a more efficient code or a clean code, please give me some advice.


class file name{
		public static void main(String[]args) throws IOException
			BufferedReader br =
				new BufferedReader(new InputStreamReader(;
			System.out.print("Please enter a positive integer");
			String str = br.readLine();
			int a =Integer.parseInt(str);
			boolean sosu = true;
			if(a == 1)sosu = false;
			for(int b = 2; b*b <= a; b++){
				if(a%b == 0){
					sosu = false;
			if(sosu == true) System.out.println("\n"+a+"Is a prime number");
			else System.out.println("\n"+a+"Is not a prime number");

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