What is the efficient way of insert some bytes into a file?

Question

Hello, everyone:
If I want to insert some bytes into a file (for example, insert the bytes before all the original content of the file, or append the bytes to a file), and the size of the original file is very big. I am wondering what is the efficient way? Where can I get some sample codes?
regards,
George

Answer 1

Thanks, DrClap.
I have tried your method and you are correct. I have written a simple program which can be used to insert "Hello World " to the start of a file ("c:\\temp\\input.txt"), and I have verified that it can work. Please help to see whether it is correct and whether it has a more efficient way.
public class TestDriver {
     public static void main(String[] args) {
          byte[] back_buffer = new byte [1024];
          byte[] write_buffer = new byte [1024];
          System.arraycopy("Hello World".getBytes(), 0, write_buffer, 0, "Hello World".getBytes().length);
          int write_buffer_length = "Hello World ".getBytes().length;
          int count = 0;
          FileInputStream fis = null;
          FileOutputStream fos = null;          
          try {
               fis = new FileInputStream (new File("c:\\temp\\input.txt"));
               fos = new FileOutputStream (new File("c:\\temp\\output.txt"));
               while ((count = fis.read (back_buffer)) >= 0)
                    fos.write(write_buffer, 0, write_buffer_length);
                    System.arraycopy (back_buffer, 0, write_buffer, 0, count);
                    write_buffer_length = count;
               //write the last block
               fos.write(write_buffer, 0, write_buffer_length);
               fis.close();
               fos.close();
               //copy content back into original file
               fis = new FileInputStream (new File("c:\\temp\\output.txt"));
               fos = new FileOutputStream (new File("c:\\temp\\input.txt"));
               while ((count = fis.read (back_buffer)) >= 0)
                    fos.write(back_buffer, 0, count);
               fis.close();
               fos.close();
               //remove temporary file
               File f = new File ("c:\\temp\\output.txt");
               f.delete();
          } catch (FileNotFoundException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
               try {
                    fis.close();
               } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
               try {
                    fos.close();
               } catch (IOException e2) {
                    // TODO Auto-generated catch block
                    e2.printStackTrace();
          } catch (IOException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
               try {
                    fis.close();
               } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
               try {
                    fos.close();
               } catch (IOException e2) {
                    // TODO Auto-generated catch block
                    e2.printStackTrace();
}regards,
George