Book Image

JasperReports for Java Developers

Book Image

JasperReports for Java Developers

Overview of this book

JasperReports is the world's most popular embeddable Java open source reporting library, providing Java developers with the power to easily create rich print and web reports. This book shows you exactly how to get started, and develop the skills to get the most from JasperReports. The book steers you through each point of report setup, to creating, designing, formatting, and exporting reports with data from a wide range of datasources, and integrating JasperReports with other Java frameworks. Starting with the basics of adding reporting capabilities to your application, and creating report templates you will first see how to produce your reports through the use of JRXML files, custom ANT targets, and then see preview them in both the browser and the native browser of JasperReports. Getting data into your reports is the next step, and you will see how to get data from a range of datasources, not only databases, but XML files, and Java Objects, among others. You will create better looking reports with formatting and grouping, as well as adding graphical elements to the report. You will export your reports to a range of different formats, including PDF and XML. Creating reports will be made even easier with a walkthrough of the iReport Designer visual designing tool. To round things off, you will see how to integrate your reports with other Java frameworks, using Spring or Hibernate to get data for the report, and Java Server Faces or Struts for presenting the report.
Table of Contents (13 chapters)
12
Index

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 CsvDataSource class, which will allow us to create reports from Comma Separated Value (CSV) files.

Note

To aid us in CSV parsing, we will use Glen Smith's excellent OpenCsv library. OpenCsv contains utility classes to ease the task of working with CSV files. OpenCsv is licensed under the Apache 2.0 license. It can be downloaded from http://opencsv.sourceforge.net/.

Writing a Custom JRDataSource Implementation

As we have seen from 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()....