// InetAddressFix.java  Charles Wicksteed  16 February 2002
// Make numeric host names (IP addresses) work in JDK 1.0.2

package java.net;

public final 
class InetAddressFix {

    InetAddressFix() {}

    public static synchronized void fix(String host)
    {
      // System.out.println("host = " + host);
      // System.out.println("size = " + java.net.InetAddress.addressCache.size());
      // System.out.println("cache = " + java.net.InetAddress.addressCache.toString());

      Object obj = java.net.InetAddress.addressCache.get(host);

      // If entry in cache, we are OK, already done this name
      if (obj != null) { return; }

      // Not in cache, work out the IP address from the string
      java.util.StringTokenizer st = new java.util.StringTokenizer(host, ".");
      if (st.countTokens() != 4) return;

      // or: byte addr[] = new byte[4];
      byte[] addr = new byte[4];

      // skip out if any component is not numeric
      for (int i = 0; i < 4; i++)
      {
        try {
          int ip = Integer.parseInt(st.nextToken());
          if (ip < 0 || ip > 255) { return; }
          addr[i] = (byte)ip;
        }
        catch (NumberFormatException e) { return; }
      }

      // add to the cache
      // eg add "1.1.1.1"/1.1.1.1 to the cache
      // each address cache entry is an array of InetAddress
      // we make an array with one element (see the InetAddress code)
      InetAddress[] hostByAddr_array = new InetAddress[1];
      hostByAddr_array[0] = new InetAddress(host, addr);
      java.net.InetAddress.addressCache.put(host, hostByAddr_array);
      // System.out.println("added \"" + host + "\"/" + hostByAddr_array[0].getHostAddress());
    }
}