Newbie question: custom classes

Question

So I decided to learn Java. I have been going strong for the past 3 days, building a web crawler (I learn by doing).
So far, I love it. I am a good halfway through writing it and i have not gotten stumped till now. I was happily coding away at my main class, when I realized I needed to make a new class.
When I put a public class in the same file with the main class, the compiler complains about it being public.
When it is a private class, I can't use it in my main class.
When I make it a public class and put it in a separate file, the compiler can't find it.
I have searched and searched but what little I can find is ambiguous, making references to strange, unfamiliar constructs.
I miss #import "class.h".

Answer 1

The main class is real long but heres it basically:
public class Crawler {
     public static StringBin crawled = new StringBin(3);
     public static String domain = "";
     public static void main(String[] args) {
          crawl("http://www.google.com/");
          crawl("http://www.google.com/ig");
     public static int crawl(String location) {
     Socket socket = null;
     try {
          String currentURL = location;
          //Check/Set uniqueness
          if (crawled.contains(currentURL)) {
               return 0;
          } else {
               crawled.add(currentURL);
          return 1;
          } catch (Exception e) {
               System.err.println(e);
               return 0;
          } finally {
               if (socket != null) {
                    try { socket.close(); }
                    catch (Exception e) { System.err.println(e); }
}And here is the StringBin class:
public class StringBin {
     private static String[] array;
     private static int size=0;
     private static int increment;
     public static void StringBin(int n) {
          increment = n;
          array = new String[n];
     public static void add(String str) {
          if (size == array.length) {
               String[] newarray = new String[array.length+increment];
               System.arraycopy(array, 0, newarray, 0, array.length);
               array = newarray;
          size++;
          array[size] = str;
          Arrays.sort(array);
     public static Boolean contains(String str) {
          int i=Arrays.binarySearch(array, str);
          if (i < 0) return false;
          return true;
}The purpose of stringbin was to get a relatively efficient way of storing a group of strings and searching within them. I don't even know if it works.
They are in the same folder.
Message was edited by:
111cix