Java FileWriter - Append Line of Text File
23,042
Solution 1
Use the constructor that takes a bool append
parameter. See the javadocs for FileWriter
for that.
fWriter = new FileWriter("info.txt", true);
Solution 2
You need writer.flush()
. PrintWriter
are auto flush by default but not Writers
Author by
rjdelight
Updated on July 22, 2022Comments
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rjdelight almost 2 years
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) { }
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Mat about 13 years
close()
will flush, there's no need for it here. -
PypeBros about 13 yearshere (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 ?