import java.io.*;public class DataIODemo {    public static void main(String[] args) throws IOException {        // write the data out        DataOutputStream out = new DataOutputStream(new				   FileOutputStream("invoice1.txt"));        double[] prices = { 19.99, 9.99, 15.99, 3.99, 4.99 };        int[] units = { 12, 8, 13, 29, 50 };        String[] descs = { "Java T-shirt",			   "Java Mug",			   "Duke Juggling Dolls",			   "Java Pin",			   "Java Key Chain" };                for (int i = 0; i < prices.length; i ++) {            out.writeDouble(prices[i]);            out.writeChar('\t');            out.writeInt(units[i]);            out.writeChar('\t');            out.writeChars(descs[i]);            out.writeChar('\n');        }        out.close();        // read it in again        DataInputStream in = new DataInputStream(new				 FileInputStream("invoice1.txt"));        double price;        int unit;        StringBuffer desc;        double total = 0.0;        try {            while (true) {                price = in.readDouble();                in.readChar();       // throws out the tab                unit = in.readInt();                in.readChar();       // throws out the tab		char chr;		desc = new StringBuffer(20);		char lineSep = System.getProperty("line.separator").charAt(0);		while ((chr = in.readChar()) != lineSep)		    desc.append(chr);                System.out.println("You've ordered " +				    unit + " units of " +				    desc + " at $" + price);                total = total + unit * price;            }        } catch (EOFException e) {        }        System.out.println("For a TOTAL of: $" + total);        in.close();    }}