org.uberfire.java.nio.file.api.FileSystemProviders Maven / Gradle / Ivy
/*
* Copyright 2015 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.uberfire.java.nio.file.api;
import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.ServiceConfigurationError;
import java.util.ServiceLoader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.uberfire.java.nio.file.FileSystemNotFoundException;
import org.uberfire.java.nio.file.spi.FileSystemProvider;
import static java.util.Collections.emptyList;
import static java.util.Collections.unmodifiableList;
import static java.util.Collections.unmodifiableMap;
import static org.kie.soup.commons.validation.PortablePreconditions.checkNotEmpty;
import static org.kie.soup.commons.validation.PortablePreconditions.checkNotNull;
/**
* Back port of JSR-203 from Java Platform, Standard Edition 7.
*
* @see Original JavaDoc
*/
public final class FileSystemProviders {
private static final Logger LOGGER = LoggerFactory.getLogger(FileSystemProviders.class);
private static final String DEFAULT = "default";
private static List installedProviders = null;
private static Map mapOfinstalledProviders = null;
private static void setup() {
try {
installedProviders = buildProviders();
mapOfinstalledProviders = buildProvidersMap();
} catch (final Throwable ex) {
LOGGER.error("Can't initialize FileSystemProviders",
ex);
}
LOGGER.debug("Initialized FileSystemProviders.\n"
+ "Installed Providers: " + installedProviders + "\n"
+ "Provider Map: " + mapOfinstalledProviders);
}
private static synchronized List buildProviders() {
final ServiceLoader providers = ServiceLoader.load(FileSystemProvider.class);
if (providers == null) {
return emptyList();
}
final List result = new ArrayList<>();
for (final FileSystemProvider provider : providers) {
result.add(provider);
}
return unmodifiableList(result);
}
private static synchronized Map buildProvidersMap() {
final Map result = new HashMap<>(installedProviders.size() + 1);
for (int i = 0; i < installedProviders.size(); i++) {
final FileSystemProvider provider = installedProviders.get(i);
if (FileSystemUtils.isK8SFileSystemProviderAsDefault(provider)) {
provider.forceAsDefault();
result.put(DEFAULT, provider);
}
result.put(provider.getScheme(), provider);
}
result.computeIfAbsent(DEFAULT, k -> installedProviders.get(0)).forceAsDefault();
return unmodifiableMap(result);
}
/**
* Non standard method that provides access to default provider (default:// scheme).
*
* @return the default file system provider
* @throws ServiceConfigurationError
*/
public static FileSystemProvider getDefaultProvider() throws ServiceConfigurationError {
if (installedProviders == null) {
setup();
}
return mapOfinstalledProviders.get(DEFAULT);
}
/**
* Non standard method to resolve a provider based on uri's scheme
*
* @param uri the uri
* @return the file system provider
*/
public static FileSystemProvider resolveProvider(final URI uri) {
checkNotNull("uri",
uri);
if (installedProviders == null) {
setup();
}
return getProvider(uri.getScheme());
}
private static FileSystemProvider getProvider(final String scheme)
throws FileSystemNotFoundException, ServiceConfigurationError {
checkNotEmpty("scheme",
scheme);
final FileSystemProvider fileSystemProvider = mapOfinstalledProviders.get(scheme);
if (fileSystemProvider == null) {
throw new FileSystemNotFoundException("Provider '" + scheme + "' not found");
}
return fileSystemProvider;
}
/**
* @throws ServiceConfigurationError
* @see Original JavaDoc
*/
public static List installedProviders() throws ServiceConfigurationError {
if (installedProviders == null) {
setup();
}
return installedProviders;
}
}