根据birt engine api开发，显示报表

public void toreport() 
	{
		ServletContext sc = ServletActionContext.getServletContext();
		String filePath = sc.getRealPath("/report") + "/";
		HttpServletResponse resp = sc.getResponse();
		resp.setContentType("text/html;charset=utf-8");
		
		this.birtReportEngine = getBirtEngine(sc, filePath);
		IReportRunnable design;
		try {
			design = birtReportEngine.openReportDesign(filePath + reportName);
			IRunTask runTask = birtReportEngine.createRunTask(design);
			HashMap paramMap = new HashMap();
			paramMap.put("agencyNum", agencyNum);
			paramMap.put("weekofyear", weekOfYear);
			paramMap.put("year", year);			
			runTask.setParameterValues(paramMap);
			runTask.validateParameters();
			runTask.run(filePath + "temp.rptdocument");
			runTask.close();
			IReportDocument rptDoc = birtReportEngine.openReportDocument(filePath + "temp.rptdocument");
			totalPage = rptDoc.getPageCount();	
			IRenderTask rendTask = birtReportEngine.createRenderTask(rptDoc);
			HTMLRenderOption options = new HTMLRenderOption();
			options.setHtmlPagination(true);
			options.setEmbeddable(true);
			options.setOutputFormat(HTMLRenderOption.OUTPUT_FORMAT_HTML);
			options.setOutputStream(resp.getOutputStream());
			rendTask.setRenderOption(options);
			rendTask.setPageNumber(this.currentPage);
			rendTask.render();
			rendTask.close();
		} catch (Exception e) {
			e.printStackTrace();
			throw new ServletException(e);
		}
	}

public static synchronized IReportEngine getBirtEngine(ServletContext sc, String path) {
		if (birtEngine == null) {
			EngineConfig config = new EngineConfig();
			config.setEngineHome(sc.getRealPath("/WEB-INF/platform"));
			config.setLogConfig(path, Level.OFF);
			IPlatformContext context = new PlatformServletContext(sc);
			config.setPlatformContext(context);

			try {
				Platform.startup(config);
			} catch (BirtException e) {
				e.printStackTrace();
			}

			IReportEngineFactory factory = (IReportEngineFactory) Platform
					.createFactoryObject(IReportEngineFactory.EXTENSION_REPORT_ENGINE_FACTORY);
			birtEngine = factory.createReportEngine(config);

		}
		return birtEngine;
	}