Main.java

    	try{
    		
    		Room room = new Room(-1,-1,-1);
    	}
    	catch(IllegalArgumentException e){
    		
    		System.out.println(e.getMessage());
    		 //JOptionPane.showMessageDialog(null, e.getMessage(), "Troll", JOptionPane.ERROR_MESSAGE);
    	}
    	

Room.java

    public Room(double len,double wid,double hei) throws IllegalArgumentException
    {
       
        if (len <= 0||wid<=0||hei<=0)
        {
            
            throw new IllegalArgumentException("Can not be less that zero");
           
        }
        
        else
        length = len;
        width = wid;
        height = hei;
        
    }