Append nội dung vào file trong java

new FileWriter(file);

new FileWriter(file, true);

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class AppendToFileExample {
    private static final String FILENAME = "D:\\testout.txt";

    public static void main(String[] args) {
        BufferedWriter bw = null;
        FileWriter fw = null;

        try {
            String data = " This is new content";
            File file = new File(FILENAME);
            // if file doesnt exists, then create it
            if (!file.exists()) {
                file.createNewFile();
            }
            // true = append file
            fw = new FileWriter(file.getAbsoluteFile(), true);
            bw = new BufferedWriter(fw);
            bw.write(data);
            System.out.println("Success...");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bw != null)
                    bw.close();
                if (fw != null)
                    fw.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}