32.4. The NavNextEvent

This diagram shows the interaction between the Controller object, the NavNextEvent object and all the other actors that are used to process this navigation event.

Note: NavNextEvent works similar to NavFirstEvent, NavLastEvent and NavPrevEvent, so the diagram above should explain the sequence of class messages for all those events. For further details, see the

  public ResultSetVector processEvent(FieldValue[] childFieldValues, 
                                      FieldValue[] orderConstraint, 
                                      int          count, 
                                      String       firstPosition, 
                                      String       lastPosition, 
                                      Connection   con, 
                                      String       dbConnectionName)
                               throws SQLException

method of the selected NavigationEvent class.

32.4.1. Event initialization

This navigation event is initialized by the following parameters:

Table 32.1. initialization parameters and their meaning

action stringthe input action string generated by the parent jsp page
step widththe number of records to show into the target jsp page

Table 32.2. navigation event parameters generated by a form

action string 
step width1

32.4.2. Steps

  • The Controller servlet calls the NavNextEvent's processEvent method.

  • The NavNextEvent object retrieve the instance of the DataSourceList object.

  • The NavNextEvent object get the DataSourceFactory related to the current table and to the current request URI.

  • The NavNextEvent object retrieve the FieldValues object (a data structure representing the values of the fields decoded from a given position string) related to the the last resultset position string. [ADD A NEW MESSAGE INTO THE DIAGRAM] Then it get the key position string for the current table from that FieldValues.

  • The NavNextEvent object calls the DataSourceFactory.getNext method to obtain the ResultSetVector object. If that ResultSetVector is null, NavNextEvent calls DataSourceFactory.getLast to obtain the last records from the current table (it simulates a NavLastEvent event).