java files

• java.io
The java.io package contains classes to support reading and writing streams, files, and pipes. These classes form a fairly structured hierarchy -- most of them are subclasses of InputStream or OutputStream.

• java.net
The java.net package contains classes to support network programming. These include dealing with sockets, Internet addresses, network datagrams, uniform resource locators (URLs), and content handlers for data from a URL. To name a few, the URL class provides a very simple interface to networking -- the object referred to by the URL can be downloaded with a single call, and the Socket class allows you to connect to a specified port on a specified Internet host and read and write data using the InputStream and OutputStream classes of the java.io package.