import java.io.*;
import java.io.IOException;
import java.util.zip.*;
import java.util.zip.CheckedOutputStream;
import java.util.zip.CheckedInputStream;

public class CheckedDemo {
	static long readCis, writeCis;

	public static void main(String args[]) {
		String newfile = "newtestfile.txt";
		String oldfile = "oldtestfile1.txt";
		byte[] buffer = new byte[1024];
		try {
			FileOutputStream fout = new FileOutputStream(newfile);
			CheckedOutputStream outputtream = new CheckedOutputStream(fout,
					new CRC32());
			FileInputStream inStream = new FileInputStream(oldfile);
			int length;
			while ((length = inStream.read(buffer)) > 0) {
				outputtream.write(buffer, 0, length);
			}
			inStream.close();
			long writeCis = outputtream.getChecksum().getValue();
			System.out.println("The value of Checksum is at writing time : "
					+ writeCis);

		} catch (IOException ex) {

			System.out.println("Exception : " + ex.getMessage());
		}
		try {
			FileInputStream fin = new FileInputStream(newfile);
			CheckedInputStream inputStream = new CheckedInputStream(fin,
					new CRC32());
			byte[] buffer2 = new byte[100];
			while (inputStream.read(buffer2) >= 0) {
				long readCis = inputStream.getChecksum().getValue();
				System.out
				.println("value of checksum Affter reading  new file : "
						+ readCis);
			}
		} catch (IOException e) {
			System.out.println("the exception has been thrown" + e);
			System.exit(1);
		}
		if (writeCis == readCis)

		{
			System.out.println("No  error in new file data");
		} else {

			System.out.println(" error in new file data");
		}
	}

}