title: CRC32 - change initial value
body: <p>I want to calculate CRC32 value of a byte array with an initial CRC value in Java, same as in this Python script:</p>
  
  <pre><code>import zlib
  
  def getCrc32():
      with open("test.py", mode='rb') as file:
          fileContent = file.read()
          crcVal = zlib.crc32(fileContent,10)
  
  if __name__ == "__main__":
      getCrc32()
  </code></pre>
  
  <p>But in Java, I can not get the same result with the following code:</p>
  
  <pre><code>RandomAccessFile f = new RandomAccessFile("test.py", "r");
  byte[] b = new byte[(int) f.length()];
  f.readFully(b);
  CRC32 c2 = new CRC32();
  c2.update(10);
  c2.update(b);
  System.out.println((int) c2.getValue());
  </code></pre>
  
  <p>How can I calculate CRC32 with an inital value in Java ?</p>