Jasper

public void makeReport(){
try{
	JasperReport jasperReport = JasperManager.compileReport("pathToJRXML");

	Map params = new HashMap();
	params.put("key",123);
	
	/**constroi o report
	*@param jasperReport o jrxml carregado
	*@param params
	*@dataSource conexação com o banco
	**/	
	JasperPrint jasperPrint = JasperManager.fillReport(jasperReport, params, dataSource);
	
	//exporta o report para um arquivo pdf no disco
	JasperManager.printReportToPdfFile(jasperPrint, "pathToExport");

	//OU
	//exibe a view do report
	JasperView.viewReport(jasperPrint);
    }catch(JRException e){
	     e.printStackTrace();
   }
   }