Java Fundamentals Hardening IO Stream Note 30: Byte stream 4 ways to copy MP4 and test efficiency

1. Demand: e:\\ brother has a wife. mp4 copied to Copy.mp4 in the current project directory

byte stream Four ways of copying files :
• Basic byte stream read and write one bytes at a time
• Basic byte stream reads and writes a single array of bytes at a time
• High-efficiency byte stream read and write one bytes at a time
• High-efficiency byte stream reads and writes a single array of bytes at a time

2. code example:

1  Packagecn.itcast_06;2 3 ImportJava.io.BufferedInputStream;4 ImportJava.io.BufferedOutputStream;5 ImportJava.io.FileInputStream;6 ImportJava.io.FileOutputStream;7 Importjava.io.IOException;8 9 /*Ten * Demand: e:\\ brother has a wife. mp4 copied to Copy.mp4 in the current project directory One  *  A * Byte stream four ways to copy files: - * Basic byte stream reads and writes one bytes at a time: Total time:117235 milliseconds - * Basic byte stream reads and writes a single array of bytes: Total time:156 milliseconds the * High-efficiency byte stream reads and writes one byte at a time: Total time:1141 milliseconds - * High-efficient byte stream reads and writes an array of bytes: Total time: milliseconds -  */ -  Public classCopymp4demo { +      Public Static voidMain (string[] args)throwsIOException { -         LongStart =System.currenttimemillis (); +         //method1 ("e:\\ brother has a wife. mp4", "Copy1.mp4"); A         //method2 ("e:\\ brother has a wife. mp4", "Copy2.mp4"); at         //method3 ("e:\\ brother has a wife. mp4", "Copy3.mp4"); -METHOD4 ("e:\\ brother has a wife. mp4", "Copy4.mp4"); -         LongEnd =System.currenttimemillis (); -SYSTEM.OUT.PRINTLN ("Total Time:" + (End-start) + "millisecond"); -     } -  in     //high-efficiency byte stream reads and writes an array of bytes at a time: -      Public Static voidmethod4 (String srcstring, string deststring) to             throwsIOException { +Bufferedinputstream bis =NewBufferedinputstream (NewFileInputStream ( - srcstring)); theBufferedoutputstream BOS =NewBufferedoutputstream ( *                 NewFileOutputStream (deststring)); $ Panax Notoginseng         byte[] Bys =New byte[1024]; -         intLen = 0; the          while(len = Bis.read (bys))! =-1) { +Bos.write (bys, 0, Len); A         } the  + bos.close (); - bis.close (); $     } $  -     //an efficient byte stream reads and writes one bytes at a time: -      Public Static voidmethod3 (String srcstring, string deststring) the             throwsIOException { -Bufferedinputstream bis =NewBufferedinputstream (NewFileInputStream (Wuyi srcstring)); theBufferedoutputstream BOS =NewBufferedoutputstream ( -                 NewFileOutputStream (deststring)); Wu  -         intby = 0; About          while(by = Bis.read ())! =-1) { $ Bos.write (by); -  -         } -  A bos.close (); + bis.close (); the     } -  $     //basic byte stream reads and writes a single array of bytes at a time the      Public Static voidmethod2 (String srcstring, string deststring) the             throwsIOException { theFileInputStream FIS =NewFileInputStream (srcstring); theFileOutputStream fos =NewFileOutputStream (deststring); -  in         byte[] Bys =New byte[1024]; the         intLen = 0; the          while(len = Fis.read (bys))! =-1) { AboutFos.write (bys, 0, Len); the         } the  the fos.close (); + fis.close (); -     } the Bayi     //basic byte stream read and write one bytes at a time the      Public Static voidmethod1 (String srcstring, string deststring) the             throwsIOException { -FileInputStream FIS =NewFileInputStream (srcstring); -FileOutputStream fos =NewFileOutputStream (deststring); the  the         intby = 0; the          while(by = Fis.read ())! =-1) { the Fos.write (by); -         } the  the fos.close (); the fis.close ();94     } the}

Java Fundamentals Hardening IO Stream Note 30: Byte stream 4 ways to copy MP4 and test efficiency