Mysql-how can I insert a mysql-time null value to the database?

Java reads json data to MySQL. The value of regist_time in json is String and the value of Date in the database. if the value of regist_time is null, the database cannot be inserted. If all regist_time values are NULL, if (regist_time & quot;) regist_time & quot; 0000-00 & quot; simpledateformatnewsimpledateformat (& quot; yyyy-MM-dd-mysqljson

Java reads json data to MySQL. The value of regist_time in json is String and the value of Date in the database. if the value of regist_time is null, the database cannot be inserted. If all regist_time values are NULL, the time is from January 1, 0000 to August 00,
If (regist_time = "") regist_time = "0000-00 ";
SimpleDateFormat format = new SimpleDateFormat ("MM dd, yyyy ");
Date date = format. parse (regist_time );
Java. SQL. Date sqlDate = new java. SQL. Date (date. getTime ());

Return sqlDate;