Add Text to Existing txt. File in JAVA?

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1

Hey guys I want to be able to add lines of text to a text file without overriding the whole file in Java?

2

My friend you are going to want to open the file for 'appending' instead of 'writing'. Appending will add lines, whereas writing writes over the current stuff.

1 Like
3

thanks, got any good examples?

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4

Source is from Stackoverflow <---- love this site btw

Are you doing this for logging purposes? If so there are several libraries for this. Two of the most popular are Log4j >and Logback.

If you just want something simple, this will work:

Java 7

try

(PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("myfile.txt", true)))) {
out.println("the text");
}catch (IOException e) {
//exception handling left as an exercise for the reader
}

Older Java

try

{
PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("myfile.txt", true)));
out.println("the text");
out.close();
} catch (IOException e) {
//exception handling left as an exercise for the reader
}

Notes:

The second parameter to the FileWriter constructor will tell it to append to the file (as opposed to writing a new file).Using a BufferedWriter is recommended for an expensive writer (such as FileWriter).Using a PrintWriter gives you access to println syntax that you're probably used to from System.out.But the BufferedWriter and PrintWriter wrappers are not strictly necessary.