Bug 89947 [search] polish filters for rules & potential matches
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/MatchFilter.java
private static final String SETTINGS_LAST_USED_FILTERS= "filters_last_used";  
	
	public static MatchFilter[] getLastUsedFilters() {
		String string= JavaPlugin.getDefault().getDialogSettings().get(SETTINGS_LAST_USED_FILTERS);
		if (string != null && string.length() > 0) {
			return decodeFiltersString(string);
		}
		return getDefaultFilters();
	}
	
	public static void setLastUsedFilters(MatchFilter[] filters) {
		String encoded= encodeFilters(filters);
		JavaPlugin.getDefault().getDialogSettings().put(SETTINGS_LAST_USED_FILTERS, encoded);
	}
	
	public static MatchFilter[] getDefaultFilters() {
		return new MatchFilter[] { IMPORT_FILTER };
	}