import javax.swing.*;

aspect secaspect
{
    // an inter-type declaration
    private String base.password;

    private int base.count = 0; // count number of accesses before 
                                // password need to be changed.

    // new procedure to change password

    private void base.changepw()
	{
	    String p = JOptionPane.showInputDialog(null,
			   "Time to change password. Enter old password:");
	    if (this.password.equals(p))
	      password = JOptionPane.showInputDialog(null, "Enter new password:");
	    else 
		{ JOptionPane.showMessageDialog(null,"you're an impostor!!!");
		  throw new Error("call the FBI!");
		}
	    count = 0;  // reset counter
	}//changepw
    
    // advice to set password when object is first created

    after(base B) : execution(base.new()) && target(B)
	{
	    B.password = JOptionPane.showInputDialog(null,
			     "Enter a password and keep it secret: ");

	}    

    
    // advice to check/change password after 4 accesses to base object services

    before(base B) : call(public * base.*(..)) && !within(base) && target(B)
	{
	    B.count++;
	    if (B.count>3)  B.changepw();
            else // check password
	    {
	       String p = JOptionPane.showInputDialog(null,
			   "Enter password:");
	       if (!B.password.equals(p))
		   {
		     JOptionPane.showMessageDialog(null,
						   "you're an impostor!!!");
   		     return;
		   }
	    }
	} // before advice
    
    declare precedence: secaspect,*;  //secaspect has precedence over all

}//secaspect