Why Java SHA1 does not Initial Vector?

I am trying to use java in built method (MessageDigest) to implement SHA1. However, in examples I have not find any method parameters to declare Initial Vector. Can anybody help me about this ?开发者_运维技巧??? Thanks in advance......

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I am in no way an expert in cryptography, but logically thinking, what woud IV be needed for in digest? The point of digest is to produce seemingly random result for each input message but, as with any other hash, it must be the same for the same input. IV on the other hand are used to modify encryption algorithm to have different results for the same input.

So, I don't think there would be any IV.