Android代码Object[]转String[]

import java.util.*;

public class sort
{
    public static String[] s(Object[] a, int i){
        
        ArrayList arrayList = new ArrayList();
        for(Object aa : a){
            arrayList.add(aa);
        }

        String[] b = new String[arrayList.size()];
        arrayList.toArray(b);
        if(i == 0){
            Arrays.sort(b);
            return b;
        }
        else if(i == 1){
            Arrays.sort(b,String.CASE_INSENSITIVE_ORDER);
            return b;
        }
        return null;
    }
}