public abstract FileSystem getFileSystem (URI uri)

Returns an existing FileSystem created by this provider.

This method returns a reference to a FileSystem that was created by invoking the newFileSystem(URI,Map) method. File systems created the newFileSystem(Path,Map) method are not returned by this method. The file system is identified by its URI. Its exact form is highly provider dependent. In the case of the default provider the URI's path component is "/" and the authority, query and fragment components are undefined (Undefined components are represented by null).

Once a file system created by this provider is closed it is provider-dependent if this method returns a reference to the closed file system or throws FileSystemNotFoundException. If the provider allows a new file system to be created with the same URI as a file system it previously created then this method throws the exception if invoked after the file system is closed (and before a new instance is created by the newFileSystem method).

If a security manager is installed then a provider implementation may require to check a permission before returning a reference to an existing file system. In the case of the default file system, no permission check is required.

Parameters:
uri     URI reference

Returns:  The file system

Exceptions:
IllegalArgumentException     If the pre-conditions for the uri parameter aren't met
FileSystemNotFoundException     If the file system does not exist
SecurityException     If a security manager is installed and it denies an unspecified permission.