Something strange happend after spring-boot auto restart

Question

I use a static threadlocal variable store per request sql query count.

As the code

public class App {

    public static ThreadLocal<Integer> count = ThreadLocal.withInitial(() -> 0);;

}

And i count it when some sql execute

public class P6spyListener extends JdbcEventListener {


    @Override
    public void onAfterExecuteQuery(PreparedStatementInformation statementInformation, long timeElapsedNanos, SQLException e) {
//        System.out.println(statementInformation.getSqlWithValues());
         log.info("又是这个问题.."+App.count.get().toString());
        App.count.set(App.count.get() + 1);
        log.info("execute query..." + statementInformation.getSqlWithValues());
    }

    @Override
    public void onAfterExecuteUpdate(PreparedStatementInformation statementInformation, long timeElapsedNanos, int rowCount, SQLException e) {
        App.count.set(App.count.get() + 1);
        log.info("execute update.." + statementInformation.getSqlWithValues());
    }

    @Override
    public void onAfterExecute(StatementInformation statementInformation, long timeElapsedNanos, String sql, SQLException e) {
        App.count.set(App.count.get() + 1);
        log.info("execute.." + statementInformation.getSqlWithValues());
    }

}

then i log the total count afterCompletion

public class RequestInitInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        log.info(String.format("count is %d",App.count.get()));
        return true;
    }



    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        log.info(String.format("finish request... 执行sql %d ", App.count.get()));
        App.count.remove();
    }
}

everything right,i can get success result

But when i edit anycode ,the springboot auto restart. then count is wrong.

the result always is zero.