writeprices.java

《A first book of java》by Gary J.Bronson 北大出版社

import java.io.*;
public class WritePrices
{
  public static void main(String[] args)
    throws java.io.IOException
  {
    String fileName = "prices.dat";
  
       // set up the basic output stream
    FileOutputStream fos = 
        new FileOutputStream(fileName);

       // buffer it for faster output
    BufferedOutputStream bos =
        new BufferedOutputStream(fos); 

       // this provides a set of useful methods 
    DataOutputStream dos =
        new DataOutputStream(bos);
 
    dos.writeDouble(39.95);
    dos.writeDouble(3.22);
    dos.writeDouble(1.08);

    dos.close(); 

    System.out.println("A new " + fileName + " file has been written.");
  }
}