CODEWITHSUNDEEP
javatext-files
Aida E
Aida E

Reputation: 1100

writing the console result into textfile

I wrote this code to convert binary data to ascii , now I want to write the console result into a textfile output.txt . it runs but the problem is it prints the first line into console and start writing the output to textfile from the second line , on other words it skip the fisr line !

public static void main(String args[])
  {
  try{
  // Open the file that is the first 
  // command line parameter
  FileInputStream fstream = new FileInputStream("textfile.txt");
  // Get the object of DataInputStream
  DataInputStream in = new DataInputStream(fstream);
  BufferedReader br = new BufferedReader(new InputStreamReader(in));
  String strLine;
  //Read File Line By Line
  while ((strLine = br.readLine()) != null)   {

      String input = br.readLine();
            String output = "";
            for(int i = 0; i <= input.length() - 8; i+=8)
            {
                int k = Integer.parseInt(input.substring(i, i+8), 2);
                output += (char) k;
            }

                System.out.println("string: " + output);
          orgStream = System.out;
          fileStream = new PrintStream(new FileOutputStream("d:/output.txt",true));

          // Redirecting console output to file
          System.setOut(fileStream);


              } 
  //Close the input stream
  in.close();
    }catch (Exception e){//Catch exception if any
  System.err.println("Error: " + e.getMessage());
  }
  }
}

these line are responsible for writing the result into output.txt:

 System.out.println("string: " + output);
          orgStream = System.out;
          fileStream = new PrintStream(new FileOutputStream("d:/output.txt",true));

          // Redirecting console output to file
          System.setOut(fileStream);

how can I save output in eclipse to be able to use that again ? now I save in D drive

Upvotes: 0

Views: 2716

Answers (4)

Torben
Torben

Reputation: 3913

This line

PrintStream out = new PrintStream(new FileOutputStream("output.txt"));
System.setOut(out);

simply redirects whatever you write to System.out to a FileOutputStream. Since you are not writing anything to System.out, nothing is written to output.txt.

Instead of redirecting System.out, you could simply write your output to the PrintStream you created. So first create the PrintStream outside the while loop and then inside the loop write each character you create directly to the PrintStream. No need to redirect System.out or (inefficiently) concatenate the characters into a String.

Also, when you are done writing, you should close() the streams you created. This is just a good practice to learn before you start writing bigger programs where leaving streams open can cause bugs.

Upvotes: 1

AbstractProblemFactory
AbstractProblemFactory

Reputation: 9811

You don't use your out stream.

Upvotes: 1

user unknown
user unknown

Reputation: 36229

I guess you need an 

out.flush ();

in the end. On a second look, I see, you never write anything to out. Do you only want to write error messages as Anantha suggests?

You forgot the:

System.out.println (output);

Upvotes: 0

Anantha Sharma
Anantha Sharma

Reputation: 10098

the code
System.err.println("Error: " + e.getMessage()); will write to the error stream and not the out stream..

          System.setOut(out);

here you are setting the out stream, the err stream still defaults to the console.

Upvotes: 0

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