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.
This navigation event is initialized by the following parameters:
Table 32.1. initialization parameters and their meaning
| action string | the input action string generated by the parent jsp page |
| step width | the number of records to show into the target jsp page |
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).