Using JSPs, XSL, and Scrollable ResultSets to Display Data - Java Database Programming Bible - page 381

cs.setString(3,make);
cs.setString(4,model);
cs.setString(5,engine);
cs.setString(6,transmission);
cs.setInt (7,price);
cs.setInt (8,year);
rs = cs.executeQuery();
rs.last();
rowCount = rs.getRow();
con.close();
}catch(ClassNotFoundException e1){
System.err.println(e1.getMessage());
}catch(SQLException e2){
System.err.println(e2.getMessage());
}
return rowCount;
}
}

In addition to the normal getter and setter methods for its properties, the JavaBean has a number of
methods to retrieve the data and to navigate around the scrollable ResultSet . These methods include:

getMatches() . This method sets the parameters of the SQL stored procedure and calls it to get
the scrollable ResultSet . It then gets the row count by navigating to the end of the ResultSet
and getting the row number using getRow() . The ResultSet is now stored in the JavaBean for
access by the other methods.

selectRow(int row) . The selectRow() method moves the cursor to the selected row. The
row argument refers to the row number within the displayed JSP page, and the integer index
provides the offset to the row corresponding to the beginning of the current JSP page. The
selectRow() method navigates to the desired row using ResultSet.absolute(index) to
move the cursor to the row corresponding to the first row in the displayed JSP page. It then uses
ResultSet.relative(row) to move to the row corresponding to the relative row within the
displayed JSP page. Finally, it sets the JavaBean's properties by getting the appropriate data from
the ResultSet .

pageForward() . The pageForward() method moves the row index to the row corresponding
to the top of the next page.

pageBack() . The pageBack() method moves the row index to the row corresponding to the top
of the previous page.

getRowCount() . The getRowCount() method returns the rowCount .

getPage() . The getPage() method returns a String representation of the current page number
in the form "Page 1 of n".

The only slightly tricky logic involved in Listing 15-3 is in the area of moving the cursor. It is important to
remember that absolute row numbers start at 1 and that relative row numbers can never be zero.

The JSP page used to display the search results is kept separate from the JSP page that instantiates
the bean and executes the query. It includes two HTML form elements containing the page buttons and
calls separate JSP pages to handle navigation through the ResultSet . The code for the display page
is shown in Listing 15-4 .

Listing 15-4: Search-results page JSP