Java--io Flow

I. INTRODUCTION of IO

BYTE: Byte, a unit of data stored in a computer, a byte with 8 bits, is a very specific storage space

Characters: Symbols used by people, abstract meanings, such as ' 1 ' in ' a ', ' $ '

Character Set and encoding:

• What characters are there?
• Specifies whether each character is stored in one or more bytes, and which bytes are stored

IO is input and output, i.e. "read" and "write"

Based on data direction: input stream, output stream, according to processed data type: Byte stream, character stream

　　

Second, byte input stream

Import Java.io.file;import Java.io.fileinputstream;import Java.io.ioexception;public class InputStreamTest {public static void Main (string[] args) {File file = new file ("Text.txt"); try {//1, create a file named Text file.createnewfile (); FileInputStream fis = new FileInputStream ("Text.txt");                Reads the next byte of data from the input stream, returns an int value of 0-255, reads the end of the -1//Fis.read (), or reads the data from the input stream into a byte array byte[] input = new Byte[1];fis.read (input); String str = new string (input); System.out.println (str);
Fis.close ();} catch (IOException e) {//TODO auto-generated catch Blocke.printstacktrace ();}}}

　　

Conversion between String and Byte []

• byte [] strbyte = Str.getbytes ();
• String st = new String (byte);

Three, byte output stream

1 ImportJava.io.FileOutputStream;2 Importjava.io.IOException;3 4  Public classOutputstreamtest {5 6      Public Static voidMain (string[] args) {7         Try {8             //Open Input Stream9FileOutputStream fos =NewFileOutputStream ("Textw.txt");Ten  One             //the data to write AString str = "Write Data: 1234"; -             byte[] out =str.getbytes (); -  the             //writes data to the specified file - Fos.write (out); -  -             //Close the stream + fos.close (); -  +}Catch(IOException e) { A             //TODO auto-generated Catch block at e.printstacktrace (); -         } -     } -  -}

View CodeIv. implement file copy via byte stream

1 ImportJava.io.FileInputStream;2 Importjava.io.FileNotFoundException;3 ImportJava.io.FileOutputStream;4 Importjava.io.IOException;5 6  Public classCopyStream {7 8      Public Static voidMain (string[] args) {9         Try {Ten             //Create an input/output stream, read data from a text.txt file, and store the read data in Textnew.txt OneFileInputStream FIS =NewFileInputStream ("Text.txt"); AFileOutputStream fos =NewFileOutputStream ("Textnew.txt"); -  -             //an array of stored data the             byte[] Shuju =New byte[50]; -  -              while(Fis.read (shuju)! =-1) { - Fis.read (Shuju); +             } -  +             //writes data from a byte array to the Textnew.txt A Fos.write (Shuju); at  - fis.close (); - fos.close (); -}Catch(FileNotFoundException e) { -             //TODO auto-generated Catch block - e.printstacktrace (); in}Catch(IOException e) { -             //TODO auto-generated Catch block to e.printstacktrace (); +         } -  the     } *  $}

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Java--io Flow