A Word About JSF and Databases
I have already mentioned
that
the <h:dataTable>
action supports values of
type java.sql.ResultSet
and
javax.servlet.jsp.jstl.sql.Result
, i.e., the JDBC
and JSTL database query result data types. This means you can use the
JSTL <sql:query>
action to execute an SQL
query directly in a JSP page or use JDBC in an action method and
expose the ResultSet
as a request, session or
application scope variable and display the result with
<h:dataTable>
.
For a very simple application, either of those approaches typically
works fine. But when you use JSF, you already have to do quite a bit
of Java programming so I recommend that you go the extra mile and
create bean classes to represent the database data instead. The
ReportEntry
, Report
, and
ReportRegistry
classes used in the sample
application illustrate one way to represent tabular data as beans.
Using beans makes the application much more maintainable than direct
database access from JSP or application logic code—if you need
to change the database schema to improve performance, or change the
SQL statements because you’re moving to a different
database vendor, the main application code remains the same and only
the database abstraction classes need to be modified (in the sample
application, all you need to do in a case like this is replace the
ReportRegistry
implementation).
That’s all I’m going to say about JSF and databases, because that’s all there is to say about databases that is JSF-specific. To learn more ...
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