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Saturday, 7 January 2017

Chapter 17 Exercise 8, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

17.8 (Update count)
Suppose you wish to track how many times a
program has been executed. You can store an int
to count the file. Increase the count by 1 each
time this program is executed. Let the program
be Exercise17_08 and store the count in Exercise17_08.dat.


import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;

public class Exercise_08 {

    public static void main(String[] args) throws IOException {

        File file = new File("Exercise17_08.dat");

        try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) {
            int count = (raf.length() != 0) ? raf.readInt() + 1 : 1;
            raf.seek(0);
            raf.writeInt(count);
            System.out.println("The count is " + count);
        }


    }
}

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