public enum PasswordMode {

   SAME, DIFFERENT;
}

@Target( { TYPE, ANNOTATION_TYPE })
@Retention(RUNTIME)
@Constraint(validatedBy = PasswordConstraintValidator.class)
@Documented
public @interface CheckPassword {
   
    String message() default "{com.abc.myapp.account.web.CheckPassword}";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};
   
    PasswordMode value();
}

@CheckPassword(value=PasswordMode.SAME)
public final class PasswordResetForm {
   
   @NotNull
   private String password;
   
   @NotNull
   private String passwordConfirmation;

        // .....

   /**
    * @return the password
    */
   public String getPassword() {
      return password;
   }

   /**
    * @param password the password to set
    */
   public void setPassword(String password) {
      this.password = password;
   }

   /**
    * @return the passwordConfirmation
    */
   public String getPasswordConfirmation() {
      return passwordConfirmation;
   }

   /**
    * @param passwordConfirmation the passwordConfirmation to set
    */
   public void setPasswordConfirmation(String passwordConfirmation) {
      this.passwordConfirmation = passwordConfirmation;
   }   
}

public final class PasswordConstraintValidator implements
      ConstraintValidator<CheckPassword, PasswordResetForm> {
   
   private PasswordMode passwordMode;

    public void initialize(CheckPassword constraintAnnotation) {
        this.passwordMode = constraintAnnotation.value();
    }

    public boolean isValid(PasswordResetForm passwordResetForm, ConstraintValidatorContext constraintContext) {
        if (passwordResetForm == null)
            return true;

        if (passwordMode == PasswordMode.SAME)
            return passwordResetForm.getPassword().equals(passwordResetForm.getPasswordConfirmation());
        else
            return !passwordResetForm.getPassword().equals(passwordResetForm.getPasswordConfirmation());
    }
}