Relatorio com Jasper e Spring

Estou tentando gerar relatório com jasper e spring mvc, é uma especie de certificado que vai ter nome, titulo do treinamento, data de conclusão e pontuação. acompanhei a aula do Alura mais nao estou conseguindo adaptar para meu problema.

//Meu botão, que chama o controller para gerar o certificado, passando o id pego pelo angularJS
Gerar Certificado

//Meu controller que recebe o id do jsp.
@RequestMapping("certificados/{id}")
	public void Certificado(HttpServletRequest request, HttpServletResponse response,@PathVariable("id") long id) throws ServletException, IOException {
		Colaborador colaborador = new TreinamentosDao().buscaCertificado(id);
		System.out.println(id);
		
		try {
            String nome = request.getServletContext().getRealPath("/WEB-INF/jasper/certificado_Treinamento.jasper");
            EntityManager connection = new JPAUtil().manager();      
            Map<String, Object> parametros = new HashMap<String, Object>();

            GeradorRelatorio gerador = new GeradorRelatorio(nome, parametros, connection);
            gerador.geraPDFParaOutputStream(response.getOutputStream());


            connection.close();
        } catch (Exception e) {
            throw new ServletException(e);
        }
	}

//Meu gerador de relatorio
public class GeradorRelatorio {

	private String nomeArquivo;
	private Map<String, Object> parametros;
	private EntityManager connection;

	public GeradorRelatorio(String nomeArquivo, Map<String, Object> parametros, EntityManager connection) {
		this.nomeArquivo = nomeArquivo;
		this.parametros = parametros;
		this.connection = connection;
	}

	public void geraPDFParaOutputStream(OutputStream outputStream) throws ServletException, IOException {

		try {
			JasperPrint jasperPrint = JasperFillManager.fillReport(this.nomeArquivo, this.parametros, (Connection) this.connection);

			JRExporter exporter = new JRPdfExporter();
			exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
			exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, outputStream);
			exporter.exportReport();

		} catch (JRException e) {
			throw new RuntimeException(e);
		}
	}

// ERRO
Aug 01, 2017 8:34:11 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [spring-context] in context with path [/api] threw exception [java.lang.ClassCastException: org.hibernate.jpa.internal.EntityManagerImpl cannot be cast to java.sql.Connection] with root cause
java.lang.ClassCastException: org.hibernate.jpa.internal.EntityManagerImpl cannot be cast to java.sql.Connection
at br.com.grupoinvestiga.gerador.GeradorRelatorio.geraPDFParaOutputStream(GeradorRelatorio.java:33)
at br.com.grupoinvestiga.controller.PaginasController.Certificado(PaginasController.java:109)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)

alguem consegue me apontar o erro.?

Amigo,

o problema está no terceiro parâmetro do método ‘fillReport’. Veja a exception, ‘java.lang.ClassCastException’.

Você não pode fazer o cast de org.hibernate.jpa.internal.EntityManagerImpl para java.sql.Connection.

Veja aqui:

tentei algumas opções desse link, mais não existem mais no hibernate foram descontinuadas.
você sabe como resolver esse problema?

JPA 2.0

entityManager.getTransaction().begin();
java.sql.Connection connection = entityManager.unwrap(java.sql.Connection.class);
...
entityManager.getTransaction().commit();