question: @ Override public int read ( ) throws IOException { while ( in != null ) { int result = in . read ( ) ; if ( result >= 0 ) { return result ; } nextStream ( ) ; } return - 1 ; }
target:  Reads a single byte from this sequence of input streams and returns it as an integer in the range from 0 to 255. It tries to read from the current stream first; if the end of this stream has been reached, it reads from the next one. Blocks until one byte has been read, the end of the last input stream in the sequence has been reached, or an exception is thrown.