New to Java

Hi Folks!

Can anybody tell me is there any class which i can use to take square root of a number? I check BigDecimal & BigInteger but didnt see any method for square root. I need to calculate square root in my following code.

public void calcSqrt(BigInteger in)
 {
  BigDecimal div, adding, divTwo;
  BigInteger input = in;
  //square root of input...
}

Thanks in advance