public class WordValidator implements Validator {    public void validate(FacesContext context, UIComponent component,          Object value) throws ValidatorException {       if ( context == null ) throw new NullPointerException( "context is null" );       if ( component == null ) throw new NullPointerException( "component is null" );       if ( value == null ) return;       List wordList = new ArrayList(); // 合言葉の一覧       wordList.add( "山" );       wordList.add( "川" );       // 検証処理       if ( !wordList.contains( value ) ){          throw new ValidatorException( new FacesMessage( "合言葉が違います。" ) );       }    } }