Python string slicing (substringing) in Java 

we have a string "I don't want to learn programming, I want to earn money"

Python slicing:
>>> line[0:10]
"I don't wa"
>>> line[0:-1]
"I don't want to learn programming, I want to earn mone"
>>> line[2:]
"don't want to learn programming, I want to earn money"
>>> line[:]
"I don't want to learn programming, I want to earn money"
>>> line[10:-3]
'nt to learn programming, I want to earn mo'

Python slicing Java implementation:
public class Solution 
{
    public static void main(String[] args) 
    {
        String s = "I don't want to learn programming, I want to earn money";
        slicer(s, 0, 10);
        slicer(s, 0, -1);
        slicer(s, 2);
        slicer(s);
        slicer(s, 10, -3);
    }

    // using VarArgs to allow using no index, only one ore both
    // indexes without method overloading
    public static void slicer(String str, int... index) 
    {
            int startIndex;
            int endIndex;

            if (index.length > 1)
            {
                startIndex = index[0];
                endIndex = index[1];
            } else if (index.length == 1) 
            {
                startIndex = index[0];
                endIndex = str.length();
            } else 
            {
                startIndex = 0;
                endIndex = str.length();
            }

            if (endIndex < 0) 
            {
                endIndex = str.length() + endIndex;
            }

            char[] sentence = str.toCharArray();
            for (int n = startIndex; n < endIndex; n++) 
            {
                System.out.print(sentence[n]);
            }
            System.out.print("\n");
    }

}