FileSystems { public static FileSystem getFileSystem(final URI uri) throws IllegalArgumentException, FileSystemNotFoundException, ProviderNotFoundException, SecurityException { checkNotNull("uri", uri); return FileSystemProviders.resolveProvider(uri).getFileSystem(uri); } private  FileSystems(); static FileSystem getDefault(); static FileSystem getFileSystem(final URI uri); static FileSystem newFileSystem(final URI uri,
                                           final Map<String, ?> env); static FileSystem newFileSystem(final Path path,
                                           final ClassLoader loader); static FileSystem newFileSystem(final URI uri,
                                           final Map<String, ?> env,
                                           final ClassLoader loader);  }
@Test public void testGetFileSystemByURI() { assertThat(FileSystems.getFileSystem(URI.create("default: assertThat(FileSystems.getFileSystem(URI.create("file: }
@Test public void getFileSystemNull() { assertThatThrownBy(() -> FileSystems.getFileSystem(null)) .isInstanceOf(IllegalArgumentException.class) .hasMessage("Parameter named 'uri' should be not null!"); }