java.sql.SQLException: Invalid argument value: java.io.NotSerializableException

Question

This is my code of SQL Connection class where I am getting error.

public class SqlConnection {
    static Connection con;
.......

    static public ResultSet getData(String sql, List<LogModel> alist)
            throws ClassNotFoundException, SQLException {
        PreparedStatement pst = con.prepareStatement(sql);
        if (alist != null) {
            for (int i = 1; i <= alist.size(); i++) {
                pst.setObject(i, alist.get(i-1)); //Exception at this Line
            }
        }
        ResultSet rs = pst.executeQuery();
        return rs;
    }
}

Here is the LogAction class where i am calling this getdata() function.

public class LogAction extends ActionSupport implements ModelDriven<LogModel>, Preparable {

    LogModel log = null;
    List<LogModel> alist = null;
    public static final String FAILURE = "failure";

    @Override
    public void prepare() throws Exception {
        log = new LogModel();
        alist = new ArrayList<LogModel>();
    }

    @Override
    public LogModel getModel() {
        return log;
    }

    public String login() throws ClassNotFoundException, SQLException {
        String sql = "Select username,password from registration where username=? and password=?";
        alist.add(log);
        System.out.println(alist);
        ResultSet rs = SqlConnection.getData(sql, alist);
        if (rs.next()) {
            return SUCCESS;
        } else
            return FAILURE;
    }
}

Answer 1

Modify your code to

static public ResultSet getData(String sql, String username, String password)
        throws ClassNotFoundException, SQLException {
    PreparedStatement pst = con.prepareStatement(sql);
    pst.setString(1, username);
    pst.setString(2, password);
    ResultSet rs = pst.executeQuery();
    return rs;
}

setting model object to the parameter of the prepared statement makes non sense.

Answer 2

I'm sure that the PreparedStatement has no idea how to setObject on your LogModel. My advice would be to decompose that into SQL primitives so it'll know what to do with it.

Your code needs a lot of work. You aren't closing JDBC resources properly. Your LogAction class makes no sense. Lots wrong with this little bit of code. I'd be worried about your app.