This section presents several examples to illustrate further how you can use the classes discussed in this chapter.
The first example computes a message digest, or hash, using the SHA-1 algorithm. Suppose that you have a message composed of three byte arrays: i1, i2, and i3. First, you create a properly initialized message digest object. Then you run the three byte arrays through the message digest object to calculate the hash, as follows:
MessageDigest sha = MessageDigest.getInstance("SHA-1"); sha.update(i1); sha.update(i2); sha.update(i3); byte hash = sha.digest();
The call to the digest method signals the end of the input message and causes the digest to be calculated. An alternative ...