TABLEMODEL AS DATASOURCE IN JASPER REPORTS

It is a common requirement in many J2SE (client,swing) applications to present data in a tabular way and also print this tabular format as a report.

Jasper reports provides implementation that makes the task of generating reports from tabular formats simple in Swing
applications. In this demonstrations, we will be using Jasper reports 3.6.1, Netbeans 6.1 and Ireport 3.6.1.

Let start by designing our report. In generating reports from tablemodels the report fields must match the column names of the tablemodel, but sometimes it becomes impractical to use the actual column names as report fields. Jasper Reports provides a way to generate reports from TableModels without having to map the actual table columns to the report fields. We can name our
report fields COLUMN_X, where x is the column index, starting with zero. Note “COLUMN” all characters should be capitals as “column” will give you error message at run time.

Also in case you have 3 columns in your table and you define a report field “COLUMN_4” , which is for column 5, null values will be displayed for each row in the report under that field. To prevent null values from displaying in a text field you can edit the expression for that field e.g. (($F{COLUMN_4}==null)? "":$F{COLUMN_4}.toString()), which means if the if the value of $F{COLUMN_4} is null ,display nothing else display the value. To do this, right click the text field and select “edit expression”, an expression editor will pop up for you to change the expression.

Below is a picture of our report at design time

After creating our report, we go to our application (using Netbeans as the IDE), we add a JTable and a JButton to our JFrame. We the create a method which accepts  the table model to create the report, tbProducts is the name of the Jtable. Check https://gilbertadjin.wordpress.com/2009/05/05/populating-a-jtable-with-a-collection-list/ to see how to populate a list of javabean object to a Jtable

private void generateReports(String name, Map param) {
        try {

      String source = "C:/sabonay/jasperreports/" + name + ".jrxml";
            if (new File(source).exists() == false) {
      xputils.showMessage("Please go to setting and Choose report Source");
                return;
            }

JasperReport jasperReport = JasperCompileManager.compileReport(source);
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, param, new JRTableModelDataSource(tbProducts.getModel()));

            JasperViewer.viewReport(jasperPrint, false);

        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("reports Error  " + e.toString());

        }

Cheers !!!