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=new byte[1024];        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=new char[1024];    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 Succeeded!!!");    }

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

DataInputStream: Loading the local img into memory

FileInputStream fis=new FileInputStream ("E:\\5.txt");        FileOutputStream fos=new FileOutputStream ("D:\\55.txt");                DataInputStream dis=new datainputstream (FIS);        DataOutputStream Dos=null;                Byte[]bytes=new byte[1024];                int data;                while ((Data=dis.read (bytes))!=-1)        {            dos=new dataoutputstream (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 {//Create input Stream object FileInputStream fis=new fileinputstream ("c:\\ Fanning. jpg");            Dis=new DataInputStream (FIS);            Create an output stream object FileOutputStream outfile=new fileoutputstream ("c:\\ Fanning Little Beauty 33.jpg");            Out=new DataOutputStream (OutFile);            int Temp=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