剑指offer - 把数组排成最小的数

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
public class Solution {
public static String PrintMinNumber(int [] numbers) {
//char a[][]=new char[101][101];
String []s1=new String[101];
String str="";
for (int i = 0; i < numbers.length; i++) {
s1[i]=String.valueOf(numbers[i]);
}
Arrays.sort(s1,new Comparator<String>() {
public int compare(String s1, String s2)
{
String c1=s1+s2;
String c2=s2+s1;
return c1.compareTo(c2);
}

});
for (int i = 0; i < numbers.length; i++) {
str+=s1[i];
}
return str;
}
}