public RAMDirectory mkdir ( String name ) throws IOException { RAMEntry entry = getEntry ( name ) ; if ( entry instanceof RAMDirectory ) { RAMDirectory ramDirectory = ( RAMDirectory ) entry ; return ramDirectory ; } else { if ( entry == null ) { RAMDirectory directory = new RAMDirectory ( _clock , name ) ; return ( RAMDirectory ) add ( directory ) ; } else { throw new IOException ( "File exists: " + name ) ; } } }
Creates an empty directory and add it to this directory with this name . If the directory already exists it does not recreate it .