How to ""save" the result in a text file in java

Question

I want to save the output result to a text file and retrieve it whenever I want to. For writing the output to .txt, I have used the following code.

 import java.io.*;

    class FileOutputDemo {  

        public static void main(String args[])
        {              
                FileOutputStream out; // declare a file output object
                PrintStream p; // declare a print stream object

                try
                {
                        // Create a new file output stream
                        // connected to "myfile.txt"
                        out = new FileOutputStream("myfile.txt");

                        // Connect print stream to the output stream
                        p = new PrintStream( out );

                        p.append ("This is written to a file");

                        p.close();
                }
                catch (Exception e)
                {
                        System.err.println ("Error writing to file");
                }
        }
    }

It is working fine and the intended text file is written. But whenever I re-compile the program, the new output is written whereas the previous output is deleted. Is there a way to save the output of the previously written file and to pick up from where the previous text file left off (After re-compiling it).

This is not a paid service that you will get quick response to your queries. This is a community!! — Narendra Pathai, Mar 08 '13 at 08:17
Take a look at this one http://stackoverflow.com/questions/1625234/how-to-append-text-to-an-existing-file-in-java — Breavyn, Mar 08 '13 at 08:18
setting file output stream to TRUE means , it will append your data , and setting it to false will simple rewrite the file , its like deleting old one and creating a new one — Hussain Akhtar Wahid 'Ghouri', Mar 08 '13 at 08:19
PS. If you're new to stackoverflow, it's nice etiquette to 'tick' the question as answered, if you are happy with one of the answers below. — vikingsteve, Mar 08 '13 at 08:44

score 4 · Accepted Answer · answered Mar 08 '13 at 08:17

4

try this:

out = new FileOutputStream("myfile.txt", true);

Javadoc: FileOutputStream.append(String name, boolean append)

answered Mar 08 '13 at 08:17

vikingsteve

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1

Are you copying my JavaDoc link, mr. steve? ;) – Andrew Thompson Mar 08 '13 at 08:21

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

See new FileOutputStream(file, true); (or fileName as name instead of a file object) as documented in the constructors for the class.

Further tips

1. Reporting

Change:

catch (Exception e)
{
    System.err.println ("Error writing to file");
}

To:

catch (Exception e)
{
    e.printStackTrace();
}

The latter provides more information with less typing.

2. GUI

If this app. is to have a GUI, the text would typically be input by the user in a JTextArea. That component extends from JTextComponent which offers almost a 'one-liner' for saving and loading text:

Are u copying my answer, mister 4-gold medals? ;) – vikingsteve Mar 08 '13 at 08:19 — vikingsteve, Mar 08 '13 at 08:19

How to ""save" the result in a text file in java

2 Answers2

Further tips

1. Reporting

2. GUI