按年月日时分秒+自增序号的一种数据库主键生成策略

当年月日时分秒相同时，其后序号自增。

 

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import java.text.SimpleDateFormat ; import java.util.Date ; public class Key { private static String previousTime = "" ; private static Integer ORDER = 0 ; /** * 获取年月日时分秒+随机数主键值 * @return */ public static String getKeyValue (){ String currentTime = new SimpleDateFormat ( "yyyyMMddHHmmss" ). format ( new Date ()); String keyValue = currentTime ; if ( currentTime . equals ( previousTime )){ ORDER ++; StringBuffer orderStr = new StringBuffer ( "" ); for ( int i = 0 ; i < 6 - ORDER . toString (). length (); i ++){ orderStr . append ( "0" ); } orderStr . append ( ORDER . toString ()); keyValue += orderStr ; } else { previousTime = currentTime ; ORDER = 1 ; StringBuffer orderStr = new StringBuffer ( "" ); for ( int i = 0 ; i < 6 - ORDER . toString (). length (); i ++){ orderStr . append ( "0" ); } orderStr . append ( ORDER . toString ()); keyValue += orderStr ; } return keyValue ; } public static void main ( String [] args ){ for ( int i = 0 ; i < 1000000 ; i ++){ System . out . println ( Key . getKeyValue ()); } } }