Working with Input and Output - Java 6 - page 414

As an alternative, you can wait for an EOFException (end-of-file exception) to be thrown
when a read method reaches the end of a stream. The loop that reads the data can be
enclosed in a try block, and the associated catch statement should handle only
EOFException objects. You can call close() on the stream and take care of other
cleanup tasks inside the catch block.

This is demonstrated in the next project. Listings 15.5 and 15.6 contain two programs
that use data streams. The PrimeWriter application writes the first 400 prime numbers as
integers to a file called 400primes.dat . The PrimeReader application reads the integers
from this file and displays them.

LISTING 15.5 The Full Text of PrimeWriter.java

1: import java.io.*;
2:
3: public class PrimeWriter {
4: public static void main(String[] arguments) {
5: int[] primes = new int[400];
6: int numPrimes = 0;
7: // candidate: the number that might be prime
8: int candidate = 2;
9: while (numPrimes < 400) {
10: if (isPrime(candidate)) {
11: primes[numPrimes] = candidate;
12: numPrimes++;
13: }
14: candidate++;
15: }
16:
17: try {
18: // Write output to disk
19: FileOutputStream file = new
20: FileOutputStream(“400primes.dat”);
21: BufferedOutputStream buff = new
22: BufferedOutputStream(file);
23: DataOutputStream data = new
24: DataOutputStream(buff);
25:
26: for (int i = 0; i < 400; i++)
27: data.writeInt(primes[i]);
28: data.close();
29: } catch (IOException e) {
30: System.out.println(“Error — “ + e.toString());
31: }
32: }
33: