writing to a file using BufferedWriter

[Rajiv Rai]

package com.rajiv.io;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.InputStream;

public class Test1 {
  public static void main(String[] args) throws Exception {
    InputStream in = System.in;
    BufferedWriter bw = new BufferedWriter(new FileWriter("output.txt"));
    

    int letter;

    while ((letter = in.read()) != -1) {
      bw.write((char) letter);
      bw.flush();
    }
  }
}

I run the above program in eclipse giving a string as input.
It's creating the file but is not writing into it.
I am not able to understand what is the reason for it?

Thanks

[Stuart A. Burkett]

Try closing your BufferedWriter instance after you've finished writing to it.

[K. Tsang]

Try moving the flush() outside the while loop.

[Rajiv Rai]

I closed the BufferedWriter instance after it is supposed to finish
writing into the file i.e after the while loop.

Yet its not working still

[Seetharaman Venkatasamy]

your program is fine to me. any error ? where is your output.txt exactly?

[Rajiv Rai]

its created in the project root directory after i run the program

[Stuart A. Burkett]

Rajiv Rai wrote:I run the above program in eclipse giving a string as input.

What do you mean by 'giving a string as input' ?
Are you passing a string as a command line parameter or are you typing it in whilst the program is running ?

[Rajiv Rai]

I am passing the string as parameter before
running the program using Eclipse run configuration.
So I assume its taken as command line parameter only

Am not giving input whilst the program is running

[Stuart A. Burkett]

Rajiv Rai wrote:I am passing the string as parameter before
running the program using Eclipse run configuration.
So I assume its taken as command line parameter only

Am not giving input whilst the program is running

Command line parameters are passed in the args parameter of your main method.
Trying to read from System.in means your program will read what you type after the program has started.

[Rajiv Rai]

Thanks a lot.

Its working now.

[Campbell Ritchie]

You do not normally need to flush a writer before closing it, as you will see here.

[Rajiv Rai]

@ Campbell

As suggested by you.. I omitted the call to flush()
and instead just closed the BufferedWriter instance
I expected the characters to be written to the file
but that is not the case

Here is the code

package com.rajiv.io;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.InputStream;

public class Test1 {
  public static void main(String[] args) throws Exception {
    InputStream in = System.in;
    BufferedWriter bw = new BufferedWriter(new FileWriter("output.txt"));
    

    int letter;

    while ((letter = in.read()) != -1) {
      bw.write((char) letter);
      //bw.flush();
    }
    bw.close();
  }
}