编写一个函数用于去除字符串中多余的空格，比如字符串"a  b    c",处理后为"a b c"

public class StringManipulation {
 public static void main(String args[]) {
  String a="a    d   b     c";
         String  b="  ";
         
         while(a.contains(b))
         {
          a=a.replaceAll(b," ");
         }
         System.out.print(a);
  }}