Java FileWriter - Append Line of Text File

Question

I have a button in a GUI, and when the button is pressed the user has the ability to add information to a text file. I have this part setup fine, but the thing that is messing with me is that when the user writes to the file it erases all the info in the text file and the only line left is the new one that was just added. I need to add the information and still keep the original info in the text file. I thought the append command was able to do this, but I'm obviously doing something wrong. Any help would be awesome!

Here's my code:

FileWriter fWriter = null;
    BufferedWriter writer = null;
    try {
        fWriter = new FileWriter("info.txt");
        writer = new BufferedWriter(fWriter);


        writer.append(javax.swing.JOptionPane.showInputDialog(this, "add info"));
        writer.newLine();
        writer.close();
    } catch (Exception e) {
    }

score 11 · Answer 1 · answered Apr 10 '11 at 18:12

11

Use the constructor that takes a bool append parameter. See the javadocs for FileWriter for that.

fWriter = new FileWriter("info.txt", true);

answered Apr 10 '11 at 18:12

Mat

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here (sun JVM @ ubuntu), it looks like when FileWriter("info.txt") alone is used, append is preferred. Any chances that woudld be platform-dependent without actual warning in the "default" constructor's documentation ? – PypeBros Apr 12 '11 at 13:18

score 2 · Answer 2 · answered Apr 10 '11 at 18:11

2

You need writer.flush(). PrintWriter are auto flush by default but not Writers

answered Apr 10 '11 at 18:11

Umesh K

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1

`close()` will flush, there's no need for it here. – Mat Apr 10 '11 at 18:45

Java FileWriter - Append Line of Text File

2 Answers2