sum all the values of an array

/**
Computes the sum of a set of data values.
*/
public class DataSet
{
/**
Constructs a DataSet object.
@param values the data values
@param first the first value in the data set
@param last the last value in the data set
*/
public DataSet(int[] values, int first, int last)
{
this.values = values;
this.first = first;
this.last = last;
}

/**
Gets the sum in the set of data values
@return the sum value in the set
*/
public int getSum()
{
if (first > last)
return 0;
DataSet tail = new DataSet(values, first + 1, last);
int tailSum = tail.getSum();
return values[first] + tailSum;
}

private int[] values;
private int first;
private int last;
}