Bug 136820 viewer supports render report in pdf format
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
this.bookmark = ParameterAccessor.getBookmark( request );
		this.reportPage = String.valueOf( ParameterAccessor.getPage( request ) );
		this.reportDocumentName = ParameterAccessor.getReportDocument( request );
		this.reportDesignName = ParameterAccessor.getReport( request );
		
		processReport( request );
		
		String title = null;
		if ( title == null || title.trim( ).length( ) <= 0 )
		{
			title = BirtResources.getString( "birt.viewer.title" ); 
		}
		this.reportTitle = ParameterAccessor.htmlEncode( title );
		this.__initParameters( request );
	}
	/**
	 * Determine the report design and doc 's timestamp
	 * 
	 * @param request
	 * @throws Exception
	 */
	protected void processReport( HttpServletRequest request ) throws Exception
	{
		File reportDocFile = new File( this.reportDocumentName );
		
		File reportDesignDocFile = new File( reportDesignName );
		if ( reportDesignDocFile != null && reportDesignDocFile.exists( )
				&& reportDesignDocFile.isFile( ) && reportDocFile != null
				&& reportDocFile.exists( ) && reportDocFile.isFile( )
				&& "get".equalsIgnoreCase( request.getMethod( ) ) )