写入时PrintWriter删除txt文件的旧内容

Question

So lets say I have a txt file that I want to write to with a PrintWriter. How come the following code deletes the old contents of the file everytime its called?

Code:

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;

public class Test {

    public static void main(String[] args) {
        writeToFile("foo");
        writeToFile("bar");
    }

    public static void writeToFile(String text) {
        try {
            PrintWriter printer = new PrintWriter(new File("myTextFile.txt"));
            printer.println("Your text is:" + text);
            printer.close();
        } catch (FileNotFoundException fnfe) {
            fnfe.printStackTrace();
        }
    }

}

Output:

Your text is:bar

I'm guessing its something to do with the fact that I'm creating a new PrintWriter or a new File every time the method is being called, but having only one instance being created in the main method failed to work as well.

Answer 1

If you want to add to a file's contents, you need to explicitly open the file for append; the default in most languages is overwrite.

To do so in Java, use new FileWriter("myfile.txt", true) . You can then wrap a PrintWriter around that if desired.