Jacksum is a free and platform independent utility for computing and verifying checksums, CRCs and message digests as well as timestamps of files.
Jacksum is entirely written in Java.
It supports most common checksum algorithms (Adler32, BSD sum, POSIX cksum, CRC-16, CRC-32, MD2, MD4, MD5, RIPEMD-128, RIPEMD-160, SHA-1, SHA-256, SHA-384, SHA-512, Unix System V sum, sum8, sum16, sum24, sum32, Whirlpool and xor8)