Java IO Stream

Overview

Widely refers to read and write operations on files

Java IO operations are not only read and write to files, but also read and write to strings, byte arrays, objects, basic data types

Operations are divided into bytes and manipulated by characters. When the requirements of high precision, every byte can not be wrong, such as in the operation of pictures, video, audio and so on by the byte stream to the IO operation, outside the IO operation takes precedence of characters, its efficiency is high

InputStream (byte input stream) implementation class:

　　FileInputStream

File byte input stream, for file

Created with new FileInputStream (file file)

　　ObjectInputStream

Acts on a single byte input stream, such as a file (which holds object information) deserialized into an object, which must implement the Serializable interface

Created with new ObjectInputStream (InputStream in)

Returning an object by ReadObject ()

　　Bytearrayinputstream

byte array input stream, for byte array

Operations IO but does not produce files, in memory, also called memory bytes input stream

Created with new Bytearrayinputstream (byte[] buf)

　　Bufferedinputstream

Buffer byte input stream, acting on one byte input stream

Created with new Bufferedinputstream (InputStream in)

Common methods:

Read (); //　　reads the next byte of the stream read (byte[] b); //　　reads the input stream and exists in byte array B in read (byteintint len); // reads a portion of the input stream and exists in byte array b

OutputStream (byte output stream) Implementation class:

　　FileOutputStream

File byte output stream, used for file, output content to file

Created by new FileOutputStream (file file) and automatically created if no files exist

Created by new FileOutputStream (file file, Boolean), which can be appended at the end if the file does not exist automatically created

　　PrintStream

Print stream, parent class is FileOutputStream, used for file or byte output stream

Created with new PrintStream, you can write content to a file

Created by the new PrintStream (output stream out), you can write content to an output stream

The print () parameter can be of many types, which means the flow is very powerful!

　　ObjectOutputStream

Object serialization stream, acting on a single byte output stream

Used to transfer an object to binary data (write file, send to others), must implement Serializable interface

Created with new ObjectOutputStream (OutputStream out)

Writes an object by WriteObject (object obj)

Bytearrayoutputstream

Array byte output stream, operation IO does not produce file, also called memory byte output stream

Bufferedoutputstream

Buffered byte output stream, acting on a single byte output stream

Created with new Bufferedoutputstream (OutputStream out)

Common methods:

Write (int b); //　　writes a byte to the output stream write (byte[] b); //　　writes an array of bytes to the output stream write (byteintint len); // writes the portion of a byte array to the output stream

Reader (character input stream) implementation class:

FileReader

File character output stream, which writes the contents of a file to a stream for use in a file

Created with new FileReader (file file)

BufferedReader

Character buffer input stream, acting on one character input stream

Can read the string directly, which is the only stream in all streams that can read the string directly

Created with new BufferedReader (Reader in)

You can read a line through ReadLine (), return a string of this line, and return NULL if read is complete

InputStreamReader

　　　　Conversion stream for converting a byte input stream into a character input flow, acting on a byte input stream

Created with new InputStreamReader (InputStream in)

CharArrayReader

　　　　Character array input stream, operation IO does not produce file

Used to write a character array to a stream, acting on a character array

Created with new CharArrayReader (char[] buf)

Common methods:

Read (); //　　reads a character from the input stream, reads the end return-1read (char[] c); //　　Reads the input stream into a character array and reads the end return-1read (charintint len); // Reads the part of the input stream into the character array, reads the end returns-1

Writer (character output stream) implementation class:

　　FileWriter

File character output stream, write stream content to file, for file

File is overwritten by new FileWriter (file file)

Created by new FileWriter (file file) will be appended in the document MO Q

　　PrintWriter

Print stream, because with PrintStream, this class uses less

　　OutputStreamWriter

Conversion stream, converting byte output to character output stream for byte output stream

Created with new OutputStreamWriter (OutputStream out)

　　Chararraywriter

Character array output stream, writes content to character array, operation IO does not produce file

Created with new Chararraywriter ()

　　BufferedWriter

Character buffered output stream for buffering a character output stream for increased efficiency

Created by new BufferedWriter (Writer out)

Common methods:

Write (int c);    // writes a character in the stream to write in C (char[] c);    // writes the contents of the stream to the character array Cwrite (charintint len);    // writes the portion of the stream to the character output Cwrite (String str);    // writes the contents of a stream to a string int int len);    // writes a portion of a stream to a string

Java IO Stream