Java Utililty Methods File System

Path findFile(FileSystem fileSystem, String path, String optionalFileSuffix)
find File

Path file = fileSystem.getPath(path);
if (!lenientExists(file)) {
 file = fileSystem.getPath(path + optionalFileSuffix);
return file;

FileSystem getFileSystem(Path file)
get File System

FileSystem fs = null;
try {
 URI fileUri = file.toUri();
 URI uri = new URI("jar:" + fileUri.getScheme(), fileUri.getPath(), null);
 fs = FileSystems.newFileSystem(uri, new HashMap<String, String>());
} catch (Exception e) {
 e.printStackTrace();
return fs;

FileSystem getFileSystem(Path path)
get File System

return FileSystems.getFileSystem(path.toUri());

Path getPath(FileSystem targetFS, String fileName)
get Path

String[] nameComps = fileName.replace('\\', '/').split("/");
if (nameComps.length == 1) {
 return targetFS.getPath(nameComps[0]);
} else {
 return targetFS.getPath(nameComps[0], Arrays.copyOfRange(nameComps, 1, nameComps.length));

boolean isFileSystemAvailable(final Path file, final String topLevelAbsolutePath)
Determines via best effort if the file system on which the file resides is available.

if (isEqualPath(file, topLevelAbsolutePath)) {
 return Files.exists(file);
return isFileSystemAvailable2(file, topLevelAbsolutePath);

boolean isFileSystemAvailable2(final Path file, final String topLevelAbsolutePath)
is File System Available

boolean available;
if (Files.exists(file)) {
 available = true;
} else {
 if (isEqualPath(file, topLevelAbsolutePath)) {
 available = false;
 } else {
 available = isFileSystemAvailable2(file.getParent(), topLevelAbsolutePath);
...

Map loadSystemResourceKeyValueCsvFileToMap(String resourcePath)
Loads the given system resource and assumes it is a csv file with a key and value column.

URL testFileUrl = ClassLoader.getSystemResource(resourcePath);
URI testFileUri = testFileUrl.toURI();
Map<String, Double> results = new HashMap<>();
Files.lines(Paths.get(testFileUri)).forEach(x -> {
 String[] strings = x.split(",");
 results.put(strings[0], Double.parseDouble(strings[1]));
});
return results;
...

FileSystem newJarFileSystem(Path jarFilePath)
new Jar File System

return FileSystems.newFileSystem(URI.create("jar:" + jarFilePath.toUri().toString()),
 new HashMap<String, Object>());

OutputStream newOutputStream(FileSystem system, Path path)
new Output Stream

FileSystemProvider provider = system.provider();
return provider.newOutputStream(path);

List systemEnvironmentPaths()
system Environment Paths

List<String> pathStrings = systemEnvironmentPathsAsStrings();
return pathStrings.stream().map(s -> Paths.get(s)).collect(Collectors.toList());