Four sets of reading and writing programs

the file class is used to access the properties of files or directories

Flow: refers to a series of flowing characters, which is a channel for sending information in FIFO mode. Between the program and the data source is connected by a stream.

first set: byte stream read Write scheme

fileinputstream: byte stream read text file

  FileInputStream fis=New fileinputstream ("e:\\ read file. txt")        ; byte []bytes=newbyte[1024x768];         int data;          while ((Data=fis.read (bytes))!=-1)        {            string str=new string (bytes,0, data);            System.out.println (str);        }        Fis.close ();    }

fileoutputstream: byte stream write to hard disk

FileOutputStream fos=New fileoutputstream ("E:\\1.txt");        String Word= "College entrance examination is the watershed of life";         byte [] bytes = word.getbytes ();        Fos.write (bytes);        Fos.close ();        System.out.println ("Write succeeded!") );            }}

Second set: Character stream read Write scheme

FileReader: character Stream reads text

    FileReader fr=New filereader ("e:\\ read file. txt")    ; Char []chars=newchar[1024x768];     int data;      while ((Data=fr.read (chars))!=-1)    {                string str=new  String (chars);        System.out.println (str);}    }

FileWriter: character Stream writes text

FileWriter fw=New FileWriter ("E:\\2.txt");                Fw.write ("New June");                System.out.println ("Write succeeded!") );        Fw.close ();    }

third set: <bufferedreader, bufferedwriter> General and FileReader and FileWriter combined use

BufferedReader: Custom Cache size, read text 8,192 Char

    FileReader fr=New filereader ("e:\\ read file. txt");    BufferedReader br=new  BufferedReader (FR);    String line;      while ((Line=br.readline ()) =null)    {        System.out.println (line);    }    Br.close ();    Fr.close ();}

BufferedWriter: Writing text

   FileWriter fw=New FileWriter ("E:\\5.txt");        BufferedWriter BW=new  BufferedWriter (FW);        Bw.write ("ok!!" );                Bw.close ();        Fw.close ();                System.out.println ("Write Success!!!") );    }

Fourth set: can read binary (img image, etc.)

DataInputStream: loading the local img into memory

FileInputStream fis=NewFileInputStream ("E:\\5.txt"); FileOutputStream Fos=NewFileOutputStream ("D:\\55.txt"); DataInputStream Dis=NewDataInputStream (FIS); DataOutputStream dos=NULL; byte[]bytes=New byte[1024]; intdata;  while((Data=dis.read (bytes))!=-1) {dos=NewDataOutputStream (FOS);        Dos.write (bytes);        } dos.close ();        Dis.close ();        Fos.close ();                Fis.close (); System.out.println ("Copy succes!!!"); }

DataOutputStream: writes the In-memory binary data to a file on the hard disk

DataOutputStream out=NULL; DataInputStream Dis=NULL; Try {            //creating an input stream objectFileInputStream fis=NewFileInputStream ("c:\\ Fanning. jpg"); Dis=NewDataInputStream (FIS); //creating an output stream objectFileOutputStream outfile=NewFileOutputStream ("C:\\ Fanning little Beauty 33.jpg"); out=NewDataOutputStream (OutFile); inttemp=Dis.read ();  while(Temp!=-1) {out.write (temp); Temp=Dis.read (); } System.out.println ("Copy succeeded");            Fis.close ();        Outfile.close (); } Catch(Exception e) {System.out.println ("File does not exist"); }finally{            Try {                if(dis!=NULL) {dis.close (); }                if(out!=NULL) {out.close (); }            } Catch(Exception E2) {e2.printstacktrace (); }        }

Note: In Java, how are byte arrays and string strings converted?

1. String Turn byte[]

String str = "Hello";
byte[] Srtbyte = Str.getbytes ();

2, byte[] turn string

Byte[] Srtbyte;
String str = new string (srtbyte);
System.out.println (str);

Four sets of reading and writing programs