Reverse Words in a String

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

click to show clarification.

Clarification:

• What constitutes a word?
  A sequence of non-space characters constitutes a word.
• Could the input string contain leading or trailing spaces?
  Yes. However, your reversed string should not contain leading or trailing spaces.
• How about multiple spaces between two words?
  

• Reduce them to a single space in the reversed string.

public class Solution {
    public String reverseWords(String s) {
        if(s==null || s.length()==0)
return "";

String[] array = s.split(" ");
StringBuilder sBuilder = new StringBuilder();
for (int i = array.length - 1; i >= 0; --i){
if(!array[i].equals(""))
sBuilder.append(array[i]).append(" ");
}
if(sBuilder.length() == 0)
return "";
else
return sBuilder.substring(0, sBuilder.length()-1);
    }
}