Smallest Number formed from an Array : Number formed from an Array

Given a list of non negative integers, arrange them in such a manner that they form the smallest number possible.

The result is going to be very large, hence return the result in the form of a string.

// Input array {20, 1, 5}
// Result:  1205


private String getSmallestNumber(Integer[] nums) { 

}

//Suggest me good algorithm asap.
