RandomeAccessFile

use write replace writeBytes

public class RandomAccessFileTest {    public static void main(String[] args) {        try {            RandomAccessFile file= new RandomAccessFile("c://temp//in.txt","rw");            System.out.println(file.readLine());                        file.seek(file.length());            //clear all//            file.setLength(0l);                        //use write() to replace writeBytes            file.write("hello ross test".getBytes());            //writeBytes will has issue on UTF8//            file.writeBytes("");            file.close();        } catch (FileNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }}