In mysql, there is a timestamp field whose value is 2019-06-20 17:24:00.

The java bean looks like:

public class SentLog {

    private Date sentDatetime;
}

However, after retrieve this value from DB, System.out.println(s.getSentDatetime()) shows a different date time. They differ 13 or 14 hours.

In mysql, run show variables like '%time_zone%'; shows

system_time_zone	CST
time_zone	        SYSTEM

In java TimeZone.class :

For compatibility with JDK 1.1.x, some other three-letter time zone IDs (such as “PST”, “CTT”, “AST”) are also supported. However, their use is deprecated because the same abbreviation is often used for multiple time zones (for example, “CST” could be U.S. “Central Standard Time” and “China Standard Time”), and the Java platform can then only recognize one of them.

Therefore, when convert CST 2019-06-20 17:24:00 to Date, java use US Time to do conversion rather than China Standard Time.

There are some solutions:

1. Define String sentDatetime instead of Date
2. Set default-time-zone='+8:00' in my.cnf, if timezone tables have values in mysql database, we can use default-time-zone='Asia/Shanghai
3. Add serverTimezone=Asia/Shanghai to your connection url string