Byte stream:
Byte output stream: OutputStream
There are many subclasses of OutputStream , and the subclass FileOutputStream can be used to write data to a file.
The FileOutputStream class , the file output stream , is an output stream used to write data to File .
FileOutputStream (String name): Create an output file stream that writes data in a file with the specified name
Byte input stream: InputStream
int read (): read a byte and return, return -1 if there is no byte.
int read (byte []): Read a certain number of bytes and store them in a byte array, and return the number of bytes read.
There are many subclasses of InputStream , and the subclass FileInputStream can be used to read the file content.
FileInputStream gets input bytes from a file in the file system.
Here is a small case of copying video from a byte stream:
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;
public class Work01 {
public static void main (String [] args) throws IOException {
// One array one array copy
Date date = new Date ();
System.out.println ("Start time:" + date.getTime ()) ;
// Explicit data source
FileInputStream fis = new FileInputStream ("D: \\ io1227 \\ video \\ AMG_GT_ALL_4_original.mp4");
// Explicit destination
FileOutputStream fos = new FileOutputStream ("D: \\ io1227 \\ mp4. mp4 ");
// Start to copy
byte [] bytes = new byte [1024];
int len = 0;
while ((len = fis.read (bytes))! =-1) {
fos.write (bytes);
}
fis.close ();
fos.close ();
Date date2 = new Date ();
System.out.println ("Array copy end time:" + date2.getTime ());
// One byte one byte copy
FileInputStream fis2 = new FileInputStream ("D: \\ io1227 \\ video \\ AMG_GT_ALL_4_original.mp4");
FileOutputStream fos2 = new FileOutputStream ("D: \\ io1227 \\ mp5.mp4");
int len2 = 0;
while ( (len2 = fis2.read ())! =-1) {
fos2.write (len2);
}
fis2.close ();
fos2.close ();
Date date3 = new Date ();
System.out.println (" Byte copy end time: "+ date3.getTime ());
System.out.println (" Array copy time: "+ (date2.getTime ()-date.getTime ()) +" ms ");
System.out .println ("Time for copying bytes:" + (date3.getTime ()-date2.getTime ()) + "ms");
}
}
This is a small video with a size of 2330KB, it is very obvious that the array is much more efficient than bytes
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