18th Java I/O stream (3)

1. Input and output stream (single byte read)

 Packagecn.itcast_02;ImportJava.io.FileInputStream;ImportJava.io.FileOutputStream;Importjava.io.IOException;/**Requirement: Copy text content to another place (single byte copy)*/ Public classCopyfiledemo { Public Static voidMain (string[] args)throwsIOException {//Get Stream ObjectFileInputStream FIS =NewFileInputStream ("A.txt"); FileOutputStream Fos=NewFileOutputStream ("B.txt"); //first read the text content (input to write the data into the flow with the stream) and then output to another place//A byte -by-byte read (returned by the byte itself) reads a write a        inti = 0; //The return value I represents the byte itself         while((I=fis.read ())!=-1){            //WriteFos.write (i);        } fis.close ();    Fos.close (); }}

2. Input and output stream (byte array read)

1  Packagecn.itcast_02;2 ImportJava.io.FileInputStream;3 ImportJava.io.FileOutputStream;4 Importjava.io.IOException;5 /**6 Requirement: Copy text content to another place (byte array copy)7 */8  Public classCopyFileDemo2 {9      Public Static voidMain (string[] args)throwsIOException {Ten         //gets the stream object to copy A.txt to B.txt OneFileInputStream FIS =NewFileInputStream ("A.txt"); AFileOutputStream fos =NewFileOutputStream ("B.txt"); -         //defines an array of bytes -         byte[] bs =New byte[1024]; the         intlen = 0;//The read method with parameters returns the number of bytes fetched -          while((Len=fis.read (BS))!=-1){ - System.out.println (len); -Fos.write (bs,0, Len); +         } - fis.close (); + fos.close (); A     } at}

3. Buffer Stream

1  Packagecn.itcast_02;2 3 ImportJava.io.BufferedInputStream;4 ImportJava.io.BufferedOutputStream;5 ImportJava.io.FileInputStream;6 ImportJava.io.FileOutputStream;7 Importjava.io.IOException;8 9 /**Ten * Stream .....  One  */ A  Public classDemo { -      Public Static voidMain (string[] args)throwsIOException { -         LongStart =System.currenttimemillis (); the         //method1 ("Aaa.mp3", "Bbb.mp3");//556 Ms -         //method2 ("Aaa.mp3", "Bbb.mp3");//197 Ms -          //method3 ("Aaa.mp3", "Bbb.mp3");//... Milliseconds -METHOD4 ("Aaa.mp3", "Bbb.mp3");//1454 Ms +         LongEnd =System.currenttimemillis (); -SYSTEM.OUT.PRINTLN (End-start); +     } A  at     //Efficient buffered stream single byte read -      Public Static voidMethod1 (string s1, string s2)throwsIOException { -         //Get Stream Object -Bufferedinputstream bis =NewBufferedinputstream (NewFileInputStream (S1)); -Bufferedoutputstream BOS =NewBufferedoutputstream (Newfileoutputstream (S2)); -         //single byte read and write in         intI =0; -          while((I=bis.read ())!=-1){ to Bos.write (i); +         } - bis.close (); the bos.close (); *     } $ Panax Notoginseng     //efficient buffer stream byte array read -      Public Static voidMETHOD2 (string s1, string s2)throwsIOException { the         //Get Stream Object +Bufferedinputstream bis =NewBufferedinputstream (NewFileInputStream (S1)); ABufferedoutputstream BOS =NewBufferedoutputstream (Newfileoutputstream (S2)); the         //Cyclic read operations +         byte[] by =New byte[1024]; -         intLen = 0; $          while(len = Bis.read (by))! =-1) { $Bos.write (by, 0, Len); -         } - bis.close (); the bos.close (); -     }Wuyi  the     //normal stream single byte read -      Public Static voidMethod3 (string s1, string s2)throwsIOException { WuFileInputStream FIS =NewFileInputStream (S1); -FileOutputStream fos =Newfileoutputstream (S2); About         //single byte read and write $         inti = 0; -          while((I=fis.read ())!=-1){ - Fos.write (i); -         } A fis.close (); + fos.close (); the     } -  $     //normal stream byte array reads the      Public Static voidMETHOD4 (string s1, string s2)throwsIOException { theFileInputStream FIS =NewFileInputStream (S1); theFileOutputStream fos =Newfileoutputstream (S2); the         //read and write byte arrays -         byte[] by =New byte[1024]; in         intLen = 0; the          while(Len=fis.read (by))!=-1){ theFos.write (by,0, Len); About         } the fis.close (); the fos.close (); the     } +  -}

18th Java I/O stream (3)