Is it a prime?

index.html

<input 
  data-bind="value: number, valueUpdate: 'afterkeydown'" 
  placeholder="Type a number...">
</input> 
<p>
Is <span data-bind="text: number"></span> a prime? 
<span data-bind="text: prime"></span>

Prime.java

package dew.demo.prime;

import net.java.html.json.Model;
import net.java.html.json.ComputedProperty;
import net.java.html.json.Property;

@Model(className="PrimeUI", properties={
  @Property(name="number", type=int.class),
})
class PrimeDemo {
  @ComputedProperty static boolean prime(int number) {
     if (number <= 1) return false;
     int squareRoot = (int)Math.sqrt(number);
     for (int i = 2; i <= squareRoot; i++) {
       if (number % i == 0) return false;
     }
     return true;
  }  
  
  static {
    new PrimeUI(2).applyBindings();
  }
}