How to set up a report engine as a web application

1 Set up the platform context, as shown in Listing 12‑2.

Listing 12‑2 Setting up the platform context for WAR file deployment

// Example class to create the report engine

public class BirtEngine

{

private static IReportEngine birtEngine = null;

public static synchronized IReportEngine
getBirtEngine( ServletContext sc )

{

if (birtEngine == null) {

EngineConfig config = new EngineConfig( );

config.setBIRTHome( "" );

IPlatformContext context = new PlatformServletContext( sc );

config.setPlatformContext( context );

try

{

Platform.startup( config );

IReportEngineFactory factory = ( IReportEngineFactory )Platform.createFactoryObject( IReportEngineFactory.EXTENSION_REPORT_ENGINE_FACTORY );

birtEngine = factory.createReportEngine( config );

}

catch ( Exception e ) { e.printStackTrace( ); }

}

return birtEngine;

}

2 Set up further configuration options on the engine after instantiating the class, as shown in Listing 12‑3.

Listing 12‑3 Setting up HTML options for WAR file deployment

// In a different class, get the report engine

IReportEngine reportEngine = BirtEngine.getBirtEngine( request.getSession( ).getServletContext( ));

// Set up the engine

EngineConfig config = reportEngine.getConfig( );

HTMLRenderOption ho = new HTMLRenderOption( );

ho.setImageHandler( new HTMLServerImageHandler( ));

ho.setImageDirectory("output/image");

ho.setBaseImageURL("http://myhost/prependme?image=");

config.setEmitterConfiguration
( RenderOption.OUTPUT_FORMAT_HTML, ho );

In this listing, request is an HttpServletRequest object.