Java by API/java.util.zip/CRC32

CRC32: update(byte[] b, int off, int len)

 
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.util.Arrays;
import java.util.zip.CRC32;
public class Main {
  public static void main(String[] args) throws Exception{
    BufferedInputStream is = new BufferedInputStream(new FileInputStream("a.exe"));
    byte[] bytes = new byte[1024];
    int len = 0;
    while ((len = is.read(bytes)) >= 0) {
      new CRC32().update(bytes, 0, len);
    }
    is.close();
    System.out.println(Arrays.toString(bytes));
  }
}

new CRC32()

       
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
public class Main {
  public static void main(String[] args) throws IOException {
    FileInputStream fin = new FileInputStream(args[0]);
    System.out.println(args[0] + ":\t" + getCRC32(fin));
    fin.close();
  }
  public static long getCRC32(InputStream in) throws IOException {
    Checksum cs = new CRC32();
    for (int b = in.read(); b != -1; b = in.read()) {
      cs.update(b);
    }
    return cs.getValue();
  }
}