RandomAccessFile.writeDouble(double v) has the following syntax.
public final void writeDouble(double v) throws IOException
In the following code shows how to use RandomAccessFile.writeDouble(double v) method.
//www . j a v a 2 s .co m import java.io.*; public class Main { public static void main(String[] args) { try { double d = 1234.5678; RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw"); raf.writeDouble(d); raf.seek(0); System.out.println(raf.readDouble()); raf.seek(0); raf.writeDouble(123.4567); raf.seek(0); System.out.println(raf.readDouble()); raf.close(); } catch (IOException ex) { ex.printStackTrace(); } } }