This interface defines the methods required to compute a checksum on a stream of data. The checksum is computed based on the bytes of data supplied by the update( ) methods; the current value of the checksum can be obtained at any time with the getValue( ) method. reset( ) resets the checksum to its default value; use this method before beginning a new stream of data. The checksum value computed by a Checksum object and returned through the getValue( ) method must fit into a long value. Therefore, this interface is not suitable for the cryptographic checksum algorithms used in cryptography and security. The classes CheckedInputStream and CheckedOutputStream provide a higher-level API for computing a checksum on a stream of data. See also java.security.MessageDigest . public interface Checksum { // Public Instance Methods long getValue ( ); void reset ( ); void update (int b ); void update (byte[ ] b , int off , int len ); } ImplementationsAdler32 , CRC32 Passed ToCheckedInputStream.CheckedInputStream( ) , CheckedOutputStream.CheckedOutputStream( ) Returned ByCheckedInputStream.getChecksum( ) , CheckedOutputStream.getChecksum( ) |