public static boolean isDefaultAttributeValue ( Object value ) { if ( value == null ) { return true ; } else if ( value instanceof Boolean ) { return ! ( ( Boolean ) value ) . booleanValue ( ) ; } else if ( value instanceof Number ) { if ( value instanceof Integer ) { return ( ( Number ) value ) . intValue ( ) == Integer . MIN_VALUE ; } else if ( value instanceof Double ) { return ( ( Number ) value ) . doubleValue ( ) == Double . MIN_VALUE ; } else if ( value instanceof Long ) { return ( ( Number ) value ) . longValue ( ) == Long . MIN_VALUE ; } else if ( value instanceof Byte ) { return ( ( Number ) value ) . byteValue ( ) == Byte . MIN_VALUE ; } else if ( value instanceof Float ) { return ( ( Number ) value ) . floatValue ( ) == Float . MIN_VALUE ; } else if ( value instanceof Short ) { return ( ( Number ) value ) . shortValue ( ) == Short . MIN_VALUE ; } } return false ; }
See JSF Spec . 8 . 5 Table 8 - 1