/** Implements {@link Files#readAttributes(Path, String, LinkOption...)}. */
public ImmutableMap<String, Object> readAttributes(File file, String attributes) {
String view = getViewName(attributes);
List<String> attrs = getAttributeNames(attributes);
if (attrs.size() > 1 && attrs.contains(ALL_ATTRIBUTES)) {
// attrs contains * and other attributes
throw new IllegalArgumentException("invalid attributes: " + attributes);
}
Map<String, Object> result = new HashMap<>();
if (attrs.size() == 1 && attrs.contains(ALL_ATTRIBUTES)) {
// for 'view:*' format, get all keys for all providers for the view
AttributeProvider provider = providersByName.get(view);
readAll(file, provider, result);
for (String inheritedView : provider.inherits()) {
AttributeProvider inheritedProvider = providersByName.get(inheritedView);
readAll(file, inheritedProvider, result);
}
} else {
// for 'view:attr1,attr2,etc'
for (String attr : attrs) {
result.put(attr, getAttribute(file, view, attr));
}
}
return ImmutableMap.copyOf(result);
}
private ImmutableMap<String, FileAttributeView> createInheritedViews(
FileLookup lookup, AttributeProvider provider) {
if (provider.inherits().isEmpty()) {
return ImmutableMap.of();
}
Map<String, FileAttributeView> inheritedViews = new HashMap<>();
createInheritedViews(lookup, provider, inheritedViews);
return ImmutableMap.copyOf(inheritedViews);
}
private void createInheritedViews(
FileLookup lookup,
AttributeProvider provider,
Map<String, FileAttributeView> inheritedViews) {
for (String inherited : provider.inherits()) {
if (!inheritedViews.containsKey(inherited)) {
AttributeProvider inheritedProvider = providersByName.get(inherited);
FileAttributeView inheritedView =
getFileAttributeView(lookup, inheritedProvider.viewType(), inheritedViews);
inheritedViews.put(inherited, inheritedView);
}
}
}
@Nullable
private Object getAttributeInternal(File file, String view, String attribute) {
AttributeProvider provider = providersByName.get(view);
if (provider == null) {
return null;
}
Object value = provider.get(file, attribute);
if (value == null) {
for (String inheritedView : provider.inherits()) {
value = getAttributeInternal(file, inheritedView, attribute);
if (value != null) {
break;
}
}
}
return value;
}
private void setAttributeInternal(
File file, String view, String attribute, Object value, boolean create) {
AttributeProvider provider = providersByName.get(view);
if (provider != null) {
if (provider.supports(attribute)) {
provider.set(file, view, attribute, value, create);
return;
}
for (String inheritedView : provider.inherits()) {
AttributeProvider inheritedProvider = providersByName.get(inheritedView);
if (inheritedProvider.supports(attribute)) {
inheritedProvider.set(file, view, attribute, value, create);
return;
}
}
}
throw new IllegalArgumentException("cannot set attribute '" + view + ":" + attribute + "'");
}
private static void addMissingProviders(Map<String, AttributeProvider> providers) {
Set<String> missingViews = new HashSet<>();
for (AttributeProvider provider : providers.values()) {
for (String inheritedView : provider.inherits()) {
if (!providers.containsKey(inheritedView)) {
missingViews.add(inheritedView);
}
}
}
if (missingViews.isEmpty()) {
return;
}
// add any inherited views that were not listed directly
for (String view : missingViews) {
addStandardProvider(providers, view);
}
// in case any of the providers that were added themselves have missing views they inherit
addMissingProviders(providers);
}