import java.io.FileInputStream;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
public class Main {
public static void main(String[] argv) throws Exception {
CheckedInputStream cis = new CheckedInputStream(new FileInputStream("filename"), new Adler32());
byte[] tempBuf = new byte[128];
while (cis.read(tempBuf) >= 0) {
}
long checksum = cis.getChecksum().getValue();
}
}