Java by API/java.util.zip/CRC32

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

   <source lang="java">

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));
 }

}

 </source>
   
  
 
  

new CRC32()

   <source lang="java">
      

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();
 }

}

 </source>