public class Test {
public static void main(String[] args) {
  String str1 = "I am a good boy";
  String [] s_str1 = str1.split(" ");
  String str2 = "Am a god boy";
  String [] s_str2 = str2.split(" ");
  int match = 0;
  for(int i=0;i<s_str1.length;i++){
    for(int j=0;j<s_str2.length;j++){
      if(s_str1[i].equalsIgnoreCase(s_str2[j])){
        match++;
      }
    }
  }
  int result = match*100/s_str1.length;           //use length of string which is
                                                                        your main str

  System.out.println(result);
}
}