import java.text.Format;import java.text.SimpleDateFormat;import java.util.Date;import java.util.HashMap;import java.util.Map; /** *  * @author Phonnie * */public class StreamId {         private static final int MAX_VALUE=9999;    private static final String FORMAT = "yyMMdd";    private static final Format DF= new SimpleDateFormat(FORMAT);    private static final byte[] lock = new byte[0];    private String prefix = null;    private Date date = null;    private int number=1;    private static Map
     
       map = new HashMap
      
       ();         private StreamId(String prefix,Date date){        this.prefix = prefix;        this.date = date;    }         public static StreamId newInstance(String prefix){        Date date = new Date();        return newInstance(prefix,date);    }          public static StreamId newInstance(String prefix,Date date){        StreamId o = null;        synchronized (lock) {            String key = getKey(prefix, date);            if(map.containsKey(key)){                o = map.get(key);                int number = o.getNumber();                if(number