Java Reference
In-Depth Information
servletOutputStream, new HashMap(), csvDataSource);
response.setContentType("application/pdf");
servletOutputStream.flush();
servletOutputStream.close();
}
catch (Exception e)
{
// display stack trace in the browser
StringWriter stringWriter = new StringWriter();
PrintWriter printWriter = new PrintWriter(stringWriter);
e.printStackTrace(printWriter);
response.setContentType("text/plain");
response.getOutputStream().print(stringWriter.toString());
}
}
}
Since the constructor for
CSVDataSource
takes an instance of
java.io.
Reader
as its only argument, and
javax.servlet.ServletContext.
getResourceAsStream()
returns a
java.io.InputStream
, we take advantage of the
java.io.InputStreamReader
class. This class takes an
InputStream
and converts
it to a
Reader
. We then pass this
Reader
to
CSVDataSource
, and proceed just as
we have in previous examples. This example assumes that the CSV file is saved as
AircraftData.csv
.
Summary
This chapter has given us a quick run through all the non-database datasources
supported by JasperReports, including how to create our own.
We have created reports that use no external datasources by using an empty
datasource and have also used instances of a class implementing
java.util.Map
as a datasource by taking advantage of the
net.sf.jasperreports.engine.data.
JRMapArrayDataSource
class. We learned to use plain Java objects as datasources
by employing the
net.sf.jasperreports.engine.JRBeanArrayDataSource
and
net.sf.jasperreports.engine.JRBeanCollectionDataSource
classes.
Besides, we also saw the use of a Swing
TableModel
and an XML document
as a datasource by implementing the
net.sf.jasperreports.engine.data.
JRTableModelDataSource
and
net.sf.jasperreports.engine.data.
JRXmlDataSource
classes respectively.
We have covered not only the datasources supported by JasperReports, but also created
custom datasources by creating our own
JRDataSource
implementation. In addition
to datasources, we also discussed how to pass data in the form of report parameters.
