Summary

Update java.nio.file.FileSystems with new factory methods to make it easier for users to work with file system providers that treat the contents of a file as a file system.

Problem

Currently the API doesn't make it easy to provide configuration settings when opening a file as a file system. Users are forced to use the newFileSystem method that takes a URI to the zip or JAR file as these are the only methods that also take a Map with configuration settings (such as the "create" property to create a zip file).

Solution

Add the following methods to java.nio.file.FileSystems:

newFileSystem(Path) 
newFileSystem(Path, Map<String, ?>) 
newFileSystem(Path, Map<String, ?>, ClassLoader)

Specification

/**
 * Constructs a new {@code FileSystem} to access the contents of a file as a
 * file system.
 *
 * <p> This method makes use of specialized providers that create pseudo file
 * systems where the contents of one or more files is treated as a file
 * system.
 *
 * <p> This method first attempts to locate an installed provider in exactly
 * the same manner as the {@link #newFileSystem(Path,Map,ClassLoader)
 * newFileSystem(Path, Map, ClassLoader)}. If found, the provider's
 * {@link FileSystemProvider#newFileSystem(Path, Map) newFileSystem(Path, Map)}
 * method is invoked to construct the new file system.
 *
 * @param   path
 *          the path to the file
 * @param   env
 *          a map of provider specific properties to configure the file system;
 *          may be empty
 *
 * @return  a new file system
 *
 * @throws  ProviderNotFoundException
 *          if a provider supporting this file type cannot be located
 * @throws  ServiceConfigurationError
 *          when an error occurs while loading a service provider
 * @throws  IOException
 *          if an I/O error occurs
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 *
 * @since 13
 */
public static FileSystem newFileSystem(Path path, Map<String,?> env)
    throws IOException


/**
 * Constructs a new {@code FileSystem} to access the contents of a file as a
 * file system.
 *
 * <p> This method makes use of specialized providers that create pseudo file
 * systems where the contents of one or more files is treated as a file
 * system.
 *
 * <p> This method first attempts to locate an installed provider in exactly
 * the same manner as the {@link #newFileSystem(Path,Map,ClassLoader)
 * newFileSystem(Path, Map, ClassLoader)}. If found, the provider's
 * {@link FileSystemProvider#newFileSystem(Path, Map) newFileSystem(Path, Map)}
 * method is invoked with an empty map to construct the new file system.
 *
 * @param   path
 *          the path to the file
 *
 * @return  a new file system
 *
 * @throws  ProviderNotFoundException
 *          if a provider supporting this file type cannot be located
 * @throws  ServiceConfigurationError
 *          when an error occurs while loading a service provider
 * @throws  IOException
 *          if an I/O error occurs
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 *
 * @since 13
 */
public static FileSystem newFileSystem(Path path)
        throws IOException


/**
 * Constructs a new {@code FileSystem} to access the contents of a file as a
 * file system.
 *
 * <p> This method makes use of specialized providers that create pseudo file
 * systems where the contents of one or more files is treated as a file
 * system.
 *
 * <p> This method iterates over the {@link FileSystemProvider#installedProviders()
 * installed} providers. It invokes, in turn, each provider's {@link
 * FileSystemProvider#newFileSystem(Path,Map) newFileSystem(Path,Map)}
 * method. If a provider returns a file system then the iteration
 * terminates and the file system is returned.
 * If none of the installed providers return a {@code FileSystem} then
 * an attempt is made to locate the provider using the given class loader.
 * If a provider returns a file
 * system, then the lookup terminates and the file system is returned.
 *
 * @param   path
 *          the path to the file
 * @param   env
 *          a map of provider specific properties to configure the file system;
 *          may be empty
 * @param   loader
 *          the class loader to locate the provider or {@code null} to only
 *          attempt to locate an installed provider
 *
 * @return  a new file system
 *
 * @throws  ProviderNotFoundException
 *          if a provider supporting this file type cannot be located
 * @throws  ServiceConfigurationError
 *          when an error occurs while loading a service provider
 * @throws  IOException
 *          if an I/O error occurs
 * @throws  SecurityException
 *          if a security manager is installed and it denies an unspecified
 *          permission
 *
 * @since 13
 */
public static FileSystem newFileSystem(Path path, Map<String,?> env,
                                       ClassLoader loader)
    throws IOException