Java--io operation

Java's IO class operations mainly include the following categories

1, the use of the file class.

2, byte operation flow: OutputStream, InputStream

3, character operation Flow: Reader, Writer

4. Serialization of objects: Serializable

InputStream

The InputStream read stream has 3 methods, respectively

First: Abstract int read ()
Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.

Reads one byte from the stream at a time and represents the byte as an integer type of 0 to 255. (for example, Chinese characters, which are split into two bytes and represented as an integer type, become two numbers)

Instance:

 public  class   Test { public  static  void   main (string[] args) {String        String  = "Test using" ;         byte  [] bs=string.getbytes ();        System.out.print (bs.length  + "" );  for  (int  i = 0; i < bs.length; i++         +"  new  String (BS) ); }}

Results: 8-78-30-54-44-54-71-45-61 test use

Second: int read (byte[] buffer)
Equivalent to read (buffer, 0, buffer.length).

Equal to read (buffer, 0, buffer.length)

Third: int read (byte[] buffer, int offset, int length)

Reads at more than length bytes from this stream and stores them in the byte array b starting at offset.

Reads the length of bytes from the stream and puts it into the B array starting at the offset position.

where the Read () method reads one byte at a time, the efficiency is very low. So it is best to use the following two methods.

Java--io operation