java - Editing an already existing text file -

i'm trying edit existing file had created , far have no clue on how it's done.

can show me how , please explain line line on code does?

import java.io.*;  public class hey {      public static void main(string[] args)throws exception{         bufferedreader br = new bufferedreader (new inputstreamreader(system.in));          system.out.println("title");         string title = br.readline();         file f = new file(title +".txt");         f.createnewfile();         filewriter fw = new filewriter(f);         bufferedwriter bw = new bufferedwriter(fw);         system.out.println("what want input in text");         string text = br.readline();         bw.write(text);         bw.flush();         bw.close();       } } 

bufferedreader br = new bufferedreader (new inputstreamreader(system.in)); 

creates read buffer standard input.

string title = br.readline(); 

reads buffer until there's return character sequence found ('\n', '\r' or "\r\n"). entire line excluding return sequence saved title.

 file f = new file(title +".txt"); 

creates file object name read console.

f.createnewfile(); 

creates file if doesn't exist yet.

filewriter fw = new filewriter(f); bufferedwriter bw = new bufferedwriter(fw); 

creates buffered writer write fw.

string text = br.readline(); 

again reads line console.

 bw.write(text); 

writes line buffer.

bw.flush(); 

ensures whole buffer flushed file (written file).

bw.close(); 

closes buffer of buffered writer. should close reader buffer br , filewriter fw.