Calling Method Several Times And Trying To Write Multiple Records To A File?

So I am calling this method several times and trying to write multiple records to a file. Problem is that every time I call the method it overwrites the file from before and doesn't add it.

public void fileWriterMethod() throws IOException{
RandomAccessFile raf = new RandomAccessFile(filename, "rw");
raf.writeInt(id);
raf.writeInt(existingMileage);
raf.writeInt(gasCost);
raf.writeInt(ndays);
raf.writeInt(rate);
raf.writeInt(totalCharge);
raf.writeInt(discount);
raf.writeInt(tax);
raf.writeInt(netCharge);
raf.writeInt(returnMileage);
raf.writeBytes(carName + "
");
//Closing the stream
raf.close();
}