import java.io.*;

public class StringPatternFilter extends PatternFilter
{
   private String _str;

   private int _l;

   public StringPatternFilter(Reader r, String str)
   {
      super(r);

      _str = str;

      _l = _str.length();
   }

   protected void test() throws IOException
   {
      // we _must_ throw an EndOfStream exception like this
      //   to get around a bug is some implementations
      //   that prevents the stream from being properly
      //   reset when we hit the end of the stream
      // without this code, the stream appears never to
      //   end -- not a good thing

      in.mark(1);

      if (in.read() < 0)
      {
         throw new EndOfStream();
      }

      in.reset();

      // Read characters, create a string, and
      //    compare.

      in.mark(_l);

      char [] rgc = new char [_l];

      in.read(rgc);

      in.reset();

      String str = new String(rgc);

      if (str.equals(_str))
      {
         throw new JunkMailException(_str);
      }
   }
}