resultset.getTimestamp和ThreadLocal警告Java

Question

I have started getting lots of warnings whenever I restart my server lately. The warning looks like this:

the web application [/xxx] created a ThreadLocal with key of type [net.sourceforge.jtds.jdbc.Support$1] (value [net.sourceforge.jtds.jdbc.Support$1@29173d71]) and a value of type [java.util.GregorianCalendar] ... but failed to remove it when the web application was stopped.

I finally found the line in the code that creates it:

cp.setCreationDate(rset.getTimestamp("CreationDate"));

rset is of type java.sql.ResultSet

Is there something wrong with how I get the date from database or is there a way to remove the calendar? We have always done it like this and I don't know why these errors has started, but they really spam the logs now.

I found this thread: Java ResultSet.getTimestamp using Calendar & Thread safety

but I still get the errors.

Answer 1

完成ResultSet对象本身后，调用rset.close() ，这将释放ResultSet保留的资源。

Answer 2

I closed the resultset. This is the code now (simplified to just show my problem):

public CompanyPerson getCompanyPerson(int personId) throws SQLException {           
    CompanyPerson person = new CompanyPerson(); 
    Connection con = null;  
    PreparedStatement pstmt = null;
    ResultSet rset = null;

    StringBuffer sql = new StringBuffer();
    sql.append(" select CreationDate from  CMCompanyPeople person ");   
    sql.append(" where  person.PersonId=?");        

    try { 
        con = dataSource.getConnection();
        pstmt = con.prepareStatement(sql.toString());
        pstmt.setInt(1,personId);

        rset = pstmt.executeQuery();

        if (rset.next()) { 
            Timestamp t = rset.getTimestamp("CreationDate");
        }

        rset.close(); 
        pstmt.close();
        con.close();          

    } catch (SQLException e) {
        throw e; 
    } finally {
        closeConnection(con);

    }

    return person;
}

When i run the code the server restarted and I got the above error.

After removing the following code i did not get any error

Timestamp t = rset.getTimestamp("CreationDate");

What is going on here?