If i do things like this : ObjectInputStream reader = new ObjectInputStream (new GZIPInputStream (new FileInputStream ("wooo2.dat"))); or FileInputStream fis = new FileInputStream ("wooo2.dat"); GZIPInputStream gis = new GZIPInputStream(fis); ObjectInputStream reader = new ObjectInputStream (gis); Then I write this: reader.close(); Will it close all those 3 streams?
Calling close releases any resources associated with the stream, so I'd say that all those other stream resources that the object stream is eventually wrapped around will be closed, also.