JDBC TransientDataAccessResourceException

I have the next class:

public class Student {
    private ApplicationContext ctx=new ClassPathXmlApplicationContext("beans.xml");
    private DataSource ds=(DataSource)ctx.getBean("mainDataSource");
    private JdbcTemplate dba=new JdbcTemplate(ds);

    public void getName(int id){
        SqlParameterSource sps=new MapSqlParameterSource().addValue("idStudent", id);
        String nume=dba.queryForObject("SELECT name FROM meditator.student WHERE idStudent=:idStudent", String.class, sps);
        System.out.println(nume);
    }
}

Why I get the next exception?.

Exception in thread "main" org.springframework.dao.TransientDataAccessResourceException: PreparedStatementCallback; SQL [SELECT nume FROM meditator.student WHERE idStudent=:idStudent]; Invalid argument value: java.io.NotSerializableException; nested exception is java.sql.SQLException: Invalid argument value: java.io.NotSerializableException

Thank you!