import java.io.*;
public class Search1
{
  public static void main(String args[])
 { 
   int count=0,first=0,second=0;
   String text="ab cd ef g"; 
   String s="";
   String subtext=text;
   System.out.println(text);
   System.out.println("请输入你要查找的字符串:");
   try
  {
    BufferedReader in=new BufferedReader(new InputStreamReader    (System.in));
    s=in.readLine();
  }
  catch(IOException e){}
  for(int i=1;i<=text.length();i+=second+1)
 {
   second=subtext.indexOf("");
   String temp=subtext.substring(first,second);
   if(s.equalsIgnoreCase(temp)) count++;
   subtext=subtext.substring(second+1);
 }

  
  if(count==0)
  System.out.print("it not exists");
  else
  System.out.print("it exists");
 }
}

    
//    for (int i = 1; i <= text.length(); i += second + 1) {
//      second = subtext.indexOf("");
//      String temp = subtext.substring(first, second);
//      if (s.equalsIgnoreCase(temp))
//        count++;
//      subtext = subtext.substring(second + 1);
//    }

    boolean isEnd = false;
    first = 0; // start pos to search from, check API doc of String.indexOf
    count = 0; 
    while (! isEnd){
      int pos = text.indexOf(s, first);
      if (pos > 0) {
        count ++;
        first = pos + 1;
        System.out.println(pos);
      } else {
        isEnd = true;
      }
    }

    if (count == 0)
      System.out.print("it does not exist");