@@ -0,0 +1,456 @@
+public class PairStar %7B%0A  public static void main (String... args) %7B%0A    // Result:hel*lo%0A    System.out.println(new PairStar ().pairStar(%22hello%22));%0A  %7D%0A  %0A  public String pairStar(String str) %7B%0A    String temp=%22%22;%0A%09  if (str.length()==0%7C%7Cstr.length()==1) return str;%0A%09  temp=str.substring(0,1);%0A%09  if (str.charAt(0)==str.charAt(1)) str=(%22%22+str.charAt(0)).concat(%22*%22).concat(str.substring(1));%0A%09  str=str.substring(1);%0A%09  return temp+pairStar (str);%0A  %7D%0A%7D%0A

Create PairStar.java