JasperReports 3.5 for Java Developers

Custom datasources

So far we've seen all of the JRDataSource implementations provided by JasperReports. If we need to extract data from a type of datasource not directly supported by JasperReports, we can create a class implementing JRDataSource to meet our needs. In this section, we will create a custom datasource allowing us to generate reports from an instance of java.util.List containing arrays of strings as its elements.

Writing a custom JRDataSource implementation

In our previous examples, all JasperReports datasources implement the JRDataSource interface. JasperReports also includes the net.sf.jasperreports.engine.JRRewindableDataSource interface. This interface extends JRDatasource, adding a single method called moveFirst(). The moveFirst() ...