

Task

Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.



The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.

Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and complements the final CRC.

For the purpose of this task, generate a CRC-32 checksum for the ASCII encoded string:

 The quick brown fox jumps over the lazy dog


import java.util.zip.* ;
 
public class CRCMaker {
   public static void main( String[ ] args ) {
      String toBeEncoded = new String( "The quick brown fox jumps over the lazy dog" ) ;
      CRC32 myCRC = new CRC32( ) ;
      myCRC.update( toBeEncoded.getBytes( ) ) ;
      System.out.println( "The CRC-32 value is : " + Long.toHexString( myCRC.getValue( ) ) + " !" ) ;
   }
}