Gerar PDF Jasper Reports com API Restful Java (JAX-RS)

@Path("/Integracao")
public class Integracao{

@GET
@Path("/teste")
public void teste(){
	TrCboServiceImpl cS = new TrCboServiceImpl();
	List datasource = null;
	try {
		datasource = cS.listAll();
	} catch (ServiceException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	
	AbstractApplicationBean aab = new AbstractApplicationBean() {		
		@Override
		public boolean useMultiempresaService() {
			// TODO Auto-generated method stub
			return false;
		}
	}; 
	
	
	try {
		aab.gerarJasper("RelTrCbo", TipoRelatorioEnum.PDF.getType(), datasource, new HashMap());
	} catch (Exception e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
}

public void gerarJasper(String name, String type, List data, Map params) throws IllegalArgumentException, RuntimeException, Exception {

    boolean found = false;
    for (int i = 0; i < VALID_TYPES.length; i++) {
        if (VALID_TYPES[i].equals(type)) {
            found = true;
            break;
        }
    }
    if (!found) {
        throw new IllegalArgumentException("Tipo solicitado '" + type + "' inválido");
    }

    // Procurar recurso de design de relatório compilado
    // dá NullPointerException na linha abaixo
    ExternalContext econtext = FacesContext.getCurrentInstance().getExternalContext();
    
    InputStream stream = econtext.getResourceAsStream(PREFIX + name + SUFFIX);
    if (stream == null) {
        throw new IllegalArgumentException("O relatório '" + name + "' não existe");
    }

    FacesContext fc = FacesContext.getCurrentInstance();
    ServletContext context = (ServletContext)fc.getExternalContext().getContext();
    String path = context.getRealPath(File.separator) + "resources/jasper" + File.separator;
    String logo = context.getRealPath(File.separator) + "resources/imagens" + File.separator;
    params.put("SUBREPORT_DIR", path);
    params.put("LOGO_DIR", logo);                
                            
    JRDataSource ds = new JRBeanArrayDataSource(data.toArray());
    JasperPrint jasperPrint = null;
    try {
        jasperPrint = JasperFillManager.fillReport(stream, params, ds);
    } catch (RuntimeException e) {
        throw e;
    } catch (Exception e) {
        throw new FacesException(e);
    } finally {
        try {
            stream.close();
        } catch (IOException e) {
        }
    }

    JRExporter exporter = null;
    HttpServletResponse response = (HttpServletResponse) econtext.getResponse();
    FacesContext fcontext = FacesContext.getCurrentInstance();
    try {
        response.setContentType(type);
        if ("application/pdf".equals(type)) {
            exporter = new JRPdfExporter();
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
            exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, response.getOutputStream());
        } else if ("text/html".equals(type)) {
            exporter = new JRHtmlExporter();
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
            exporter.setParameter(JRExporterParameter.OUTPUT_WRITER, response.getWriter());
            // Tornar imagens disponíveis para a saída HTML
            HttpServletRequest request = (HttpServletRequest) fcontext.getExternalContext().getRequest();
            request.getSession().setAttribute(ImageServlet.DEFAULT_JASPER_PRINT_SESSION_ATTRIBUTE, jasperPrint);
            exporter.setParameter(JRHtmlExporterParameter.IMAGES_MAP, new HashMap());
            // A seguinte instrução requer mapeamento / imagem
            // para o imageServlet no web.xml.
            //
            // Este servlet serve imagens, incluindo imagens px
            // para espaçamento.
            //
            // Sirva as imagens diretamente para não
            // incorrermos em tempo extra associado a
            // a uma solicitação JSF para uma entidade não-JSF.
            exporter.setParameter(JRHtmlExporterParameter.IMAGES_URI, request.getContextPath() + "/image?image=");
        }else if("application/xlsx".equals(type)){
        	exporter = new JRXlsxExporter();
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
            exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, response.getOutputStream());
        }else if("application/docx".equals(type)){
        	exporter = new JRDocxExporter();
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
            exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, response.getOutputStream());
        } else if("application/rtf".equals(type)){
        	exporter = new JRRtfExporter();
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
            exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, response.getOutputStream());
        }
    } catch (RuntimeException e) {
        throw e;
    } catch (Exception e) {
        throw new FacesException(e);
    }

    try {
        exporter.exportReport();
    } catch (RuntimeException e) {
        throw e;
    } catch (Exception e) {
        throw new FacesException(e);
    }
    fcontext.responseComplete();
}