Use buffered streams to copy a file : BufferedInputStream « File « Java Tutorial

1. Java Tutorial
2. File
3. BufferedInputStream

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class Main {
  public static void main(String[] argv) throws Exception {
    BufferedInputStream fin = new BufferedInputStream(new FileInputStream("in.dat"));
    BufferedOutputStream fout = new BufferedOutputStream(new FileOutputStream("out.dat"));
    int i;
    do {
      i = fin.read();
      if (i != -1)
        fout.write(i);
    } while (i != -1);
    fin.close();
    fout.close();
  }
}