ERROR:Unreportted Exception java.io.IOEcxeption

Question

import java.io.*;
public class MyFileWriter{
     BufferedReader br;
     InputStreamReader isr;
     PrintWriter pw;
     FileWriter fw;
     File f;
     String data;
public MyFileWriter(){
     isr=new InputStreamReader(System.in);
     br=new BufferedReader(isr);
     f=new File("one.txt");
     fw=new FileWriter(f);
     pw=new PrintWriter(fw);
     readData();
public void readData(){
     try{
     while(true){
     System.out.println("enter the data except #");
     data=br.readLine();
     if(data.equals("#"))
     break;
     writeData();
catch(IOException ie){
     System.out.println(ie);
public void writeData(){
     try{
     pw.println(data);
     *}catch(IOException ie){*
     System.out.println(ie);
     public static void main(String []args){
     MyFileWriter mfw=new MyFileWriter();

Answer 1

fw=new FileWriter(f);This might throw an IOException so better you write this in to try catch block or report the method that it might throw exception
This can be done as
     public MyFileWriter() throws IOException
          isr=new InputStreamReader(System.in);
          br=new BufferedReader(isr);
          f=new File("one.txt");
          fw=new FileWriter(f);
          pw=new PrintWriter(fw);
          readData();
     }or by
     public MyFileWriter()
          try
               isr=new InputStreamReader(System.in);
               br=new BufferedReader(isr);
               f=new File("one.txt");
               fw=new FileWriter(f);
               pw=new PrintWriter(fw);
               readData();
          } catch(IOException ioe)
                        System.out.println("Any thing here");
     }And go according to your requirement
Now for this code
     public void writeData()
          try
               pw.println(data);
          } catch(IOException ie)
               System.out.println(ie);
     }here pw.println() method doesnot throws any type of exception particularly IOException
So thats why you are getting this error
exception java.io.IOException is never thrown in body of corresponding try statement
                } catch(IOException ie)so either remove "IOException ie" from there or use only "Exception e"
Hope this might help you
Better you refer java docs while coding.