Question

In selenium framework 2.25, I see that we have the UnexpectedAlertBehaviour enum type, but I don’t know how to use it.

Answer 1

I found this portion of documentation on your issue:
This may be useful for other people as well:

v2.25.0

=======

WebDriver:

• Added API for dealing with BASIC and DIGEST authentication

  dialogs. Currently not implemented in any drivers.

• Warn users that the IE driver will no longer use the DLL in the

  next release.

• Deprecated browser specific WebElement subclasses.

• Added support for “requiredCapabilities” to the remote webdrivers

  and implemented basic support for these in the firefox

  driver. Failure to fulfull a required capability will cause a

  SessionNotCreatedException to be thrown.

• Added the ability to determine how unhandled alerts should be
  handled. This is handled by the “unexpectedAlertBehaviour”
  capability, which can be one of “accept”, “dismiss” or
  “ignore”. Java code should use the UnexpectedAlertBehaviour
  enum. This is only implemented in Firefox for now.

• Allow native events to be configured in Firefox and

  (experimentally) in IE using the “nativeEvents” capability.

• Updated supported versions of Firefox to 17.

…..

Whole list provided here

An here is the source

package org.openqa.selenium;

    public enum UnexpectedAlertBehaviour {

      ACCEPT ("accept"),
      DISMISS ("dismiss"),
      IGNORE ("ignore")
      ;

      private String text;

      private UnexpectedAlertBehaviour(String text) {
        this.text = text;
      }

      @Override
      public String toString() {
        return String.valueOf(text);
      }

      public static UnexpectedAlertBehaviour fromString(String text) {
        if (text != null) {
          for (UnexpectedAlertBehaviour b : UnexpectedAlertBehaviour.values()) {
            if (text.equalsIgnoreCase(b.text)) {
              return b;
            }
          }
        }
        return null;
      }
    }

As I see you use unexpectedAlertBehaviour to decide whether alert is unhandled and if it is so, you’ll decide how to handle it.

I suppose it should be something like (my assumption):

try{
alert.accept();
}

catch(org.openqa.selenium.UnexpectedAlertBehaviour){
///...blablabla
}