new FileWriter(String fileName, boolean append)

public FileWriter(File file,boolean append) throws IOException

Constructs a FileWriter given a File object. If the second argument is true, then bytes will be written to the end of the file not the beginning.

import java.io.BufferedWriter;
import java.io.FileWriter;

public class Main {
  public static void main(String[] argv) throws Exception {
    BufferedWriter out = new BufferedWriter(new FileWriter("filename", true));
    out.write("aString");
    out.close();
  }
}

1. FileWriter
2. new FileWriter(File file)
3. new FileWriter(String string)
4. new FileWriter(String fileName, boolean append)
5. FileWriter: close()
6. FileWriter: flush()
7. FileWriter: write(int i)