Four sets of read and write file schemes

Four sets of read-write files scheme: instance

One: Reading a text file with a byte stream

Byte input stream exercise: Reading various data from a text file (letters, strings are supported)

Declaring a Stream object

Try {

FileInputStream fis=New fileinputstream ("C:\\ming.txt");

int data;

System. out. println ("Number of bytes readable:" +fis.available ());

System. out. println ("File contents:");

Looping through data

byte [] buffer=new byte[1024];

StringBuilder sb=New StringBuilder ();

while ((data=fis.read (buffer))!=-1) {

Byte[] Convert to String

String str=New string (Buffer,0,data, "gb2312");

Sb.append (str);

}

System. out. println (Sb.tostring ());

} catch (Exception e) {

}

One: Write a text file with a byte stream

Write data in memory to the hard disk by byte stream

FileOutputStream fos=null;

Try {

String str= "You are the April day of the Earth";

byte [] Words=str.getbytes ("gb2312");

Create a Stream object, write a file in Append mode

fos=New fileoutputstream ("C:\\ming.txt",true);

Write file

Fos.write (words,0,words.length);

System. out. println ("file updated");

} catch (Exception e) {

System. out. println ("Error creating file! ");

}finally{

Try {

if (fos!=null) {

Fos.close ();

}

} catch (Exception E2) {

E2.printstacktrace ();

}

}

Second: Reading a text file using a character stream

Reading a text file using a character stream

Reader fr=null;

Try {

fr=New filereader ("C:\\ming.txt");

Char [] ch=new Char[1024];//broker, Buffer

StringBuffer sbf=New stringbuffer ();

int length=fr.read (CH);//Read the characters into the array

Loop Read and append characters

while (Length!=-1) {

Sbf.append (ch,0,length);

Length=fr.read (CH);

}

System. out. Print (SBF);

} catch (Exception e) {

E.printstacktrace ();

}finally{

Try {

if (fr!=null) {

Fr.close ();

}

} catch (Exception E2) {

TODO: Handle exception

}

}

Two: Write a text file using a character stream

Write a text file using a character stream

FileWriter fw=null;

Try {

fw=New FileWriter ("C:\\ming.txt",true);

Write information

String words= "Frances Yip-Shanghai Beach";

Fw.write (words);

Fw.flush ();

System. out. println ("write success");

} catch (Exception e) {

System. out. println ("File does not exist");

}finally{

Try {

if (fw!=null) {

Fw.close ();

}

} catch (Exception E2) {

E2.printstacktrace ();

}

}

Three: Character input stream BufferedReader read file

FileReader fr=null;

BufferedReader br=null;

Try {

Create a FileReader object

fr=New filereader ("C:\\ming.txt");

Create a BufferedReader object

br=New BufferedReader (FR);

Reading a row of data

String Line=br.readline ();

while (line!=null) {

System. out. println (line);

Line=br.readline ();

}

} catch (Exception e) {

E.printstacktrace ();

}finally{

Try {

if (br!=null) {

Br.close ();

}if (fr!=null) {

Fr.close ();

}

} catch (Exception E2) {

E2.printstacktrace ();

}

}

Three: Use Mybufferedwriter to write text files

FileWriter fw=null;

BufferedWriter bw=null;

Try {

fw=New FileWriter ("C:\\ming.txt",true);

bw=New BufferedWriter (FW);

Write information

Bw.write ("The original scenery of the hometown");

Bw.newline ();

Bw.write ("Moonlight in town-Mavis Hsu");

Bw.flush ();

fw.close ();  

Read File contents

FileReader fr=New filereader ("C:\\ming.txt");

BufferedReader br=New BufferedReader (FR);

String Line=br.readline ();

while (line!=null) {

System. out. println (line);

Line=br.readline ();

}

} catch (Exception e) {

System. out. println ("File does not exist");

E.printstacktrace ();

}finally{

Try {

if (bw!=null) {

Bw.close ();

}

if (fw!=null) {

Fw.close ();

}

} catch (Exception E2) {

TODO: Handle exception

}

}

Four://Use Byte stream class DataOutputStream write binary file

DataOutputStream out=null;

DataInputStream dis=null;

Try {

Creating an input Stream object

FileInputStream fis=New fileinputstream ("c:\\ Fanning. jpg");

dis=new datainputstream (FIS);

Creating 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 ();

}

}

Four sets of read and write file schemes