day20 Java learning (IO (byte stream))

IO streams (IO streams Summary and Classification)

     concept:

             * IO stream between devices for processing data transmission .

             * Java operations on the data stream by the way.

             * Java class for IO operations in the flow package,

             * According to the flow into two flows: the input of the output stream.

             * Operation type is divided into two streams by:

                     * Byte stream: byte stream can operate any data , since any data in a computer is stored in the form of bytes.

                     * Character stream: a stream of characters can only be operated pure character data , more convenient.

 

      IO streams common parent:

              * Abstract parent class byte stream:

                     * InputStream

                     * OutputStream

              * Character stream of abstract superclass:

                     * Reader

                     * Writer       

      IO program written:         

              * Before use, import classes package IO

              * Use, make IO exception handling

              * After use, the release of resources

 

IO流(FileInputStream)

       

    public  static  void main (String [] args) throws IOException {
         // the FileInputStream 

        the FileInputStream FIS = new new the FileInputStream ( "xxx.txt"); // Create a stream object 
          int B;
           the while ! ((B = fis.read ()) = -1) {          // read the contents of the file 
            System.out.println (B); 
        } 
          fis.close (); 
    }

example

 

IO流(FileOutputStream)

    public  static  void main (String [] args) throws IOException {
         // create output byte stream object (if not, automatically creates a) 
        a FileOutputStream List = new new a FileOutputStream ( "yy.txt" ); 
        list.write ( 97);    // Although int number is written, but the document is to a byte, in addition to automatically take the first three eight. 
        list.write (98 ); 
        list.write ( 99 ); 
        list.close (); 
    }

example

    * Append: If you continue to write to the folder contents, you pass true as the second parameter.

（ FileOutputStream list=new FileOutputStream("yy.txt"，true);）

     

IO streams ( copy images )    

public  static  void main (String [] args) throws IOException { 
        
        the FileInputStream FIS = new new the FileInputStream ( "Photo .jpg");     // Create a byte stream input object 
        
        a FileOutputStream fos = new new a FileOutputStream ( "copy.jpg"); // Create byte stream output target 
        int B; 
        
        the while ((B = fis.read ()) = -1!) {                          // continue to read each byte 
            fos.write (B);                                         // each byte write 
        } 
        fis.close ();                                              // off to release resources flow
        fos.close();
    }

example

 

 

             * IO stream to handle data transfer between devices.