Java tutorial
import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; public class Main { public static void main(String[] args) throws Exception { long l = 12345678909876L; FileOutputStream out = new FileOutputStream("test.txt"); ObjectOutputStream oout = new ObjectOutputStream(out); // write something in the file oout.writeLong(l); oout.writeLong(987654321L); oout.flush(); oout.close(); // create an ObjectInputStream for the file we created before ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt")); // read and print a long System.out.println(ois.readLong()); // read and print a long System.out.println(ois.readLong()); ois.close(); } }