About input and output streams Notes:

About input and output streams Notes:

Master the following basic syntax:

1. Read byte by byte

a) reading a byte only

      InputStream in = new InputStream(“xxx”); 

Int i = In.read (); // read a byte hash value is returned

b) reading all the bytes

InputStream in = new InputStream(“xxx”);  

Int s;

While ((s = in.read) = -! 1) {// if in.read () -1 result indicates the last byte has been read

      Sysotem.out.print (s); // returns the value of the equation on the left

}

      2. Byte stream read data buffer

c)      byte[ ] b = new byte[ length];

int len;

  the while (! (len = in.read (B)) = -. 1) {//in.read(b): Reads the specified length of bytes of data to the array

     . The System OUT .write (B, 0, len); // output array, and a predetermined length of the output array

  }

Several forms of output:

1.System.out.print (xxx); the output stream of bytes

2.System.out.write (xxx, ....); Output is a character stream

3.out.write (xxx); folder output to the output stream

 

Removal of the file:

            For a single file, () method removes a xxx.delete, for non-empty folder, judgment needs to be non-empty, only delete empty folder, reference to the following specific method:

. 1   public  static  Boolean del (File F) {
 2  
. 3        // For folders, need to obtain all the files in the folder 
. 4  
. 5        IF (f.isDirectory ()) {
 . 6  
. 7          File [] FS = f.listFiles ();
 . 8  
9          // empty folder 
10  
. 11          IF (FS == null || fs.length == 0 ) {
 12 is  
13 is             return f.delete ();
 14  
15          } the else {
 16  
. 17             for (file file: FS) {
 18 is  
. 19                del (file);// recursive call 
20 is  
21 is             }
 22 is  
23 is          }
 24  
25        }
 26 is  
27        // For non folder can delete 
28  
29        return f.delete ();
 30  
31 is     }

Time is limited, first write