Java tutorial
import java.io.File; import java.io.RandomAccessFile; public class Main { public static void append(String fileName, String text) throws Exception { File f = new File(fileName); long fileLength = f.length(); RandomAccessFile raf = new RandomAccessFile(f, "rw"); raf.seek(fileLength); raf.writeBytes(text); raf.close(); } public static void append(String fileName, byte[] bytes) throws Exception { File f = new File(fileName); long fileLength = f.length(); RandomAccessFile raf = new RandomAccessFile(f, "rw"); raf.seek(fileLength); raf.write(bytes); raf.close(); } public static void main(String[] args) throws Exception { append("c:\\tmp.txt", "Appended Data"); append("c:\\tmp.bin", "Appended Data".getBytes()); } }