IO common IO operation class inheritance structure
IO character stream Reader (source) BufferedReader LineNumberReader InputStreamReader FileReader (bridge from byte stream to character stream) StringReader Writer(purpose) BufferedWriter OutputStreamWriter FileWriter (bridge from character stream to byte stream) StringWriter empty PrintWriter empty Byte stream InputStream (source) FileInputStream empty SequenceInputStream merge streams When ByteArrayInputStream is constructed, it needs to receive a data source, and the data source is a byte array;OutputStream (purpose) FileOutputStream empty ByteArrayOutputStream internally defines a variable-length byte array, which is the data destination;