我正在开发一个JSF项目，我必须在其中生成报告。要做到这一点，我正在使用JasperReports。当我单击创建PDF文件的按钮时，我可以创建while，但是我收到此错误。我不是什么原因。
GRAVE: Error Rendering View[/secure/audit/list.xhtml]
java.lang.IllegalStateException: getOutputStream() ya ha sido llamado para esta respuesta
at org.apache.catalina.connector.Response.getWriter(Response.java:565)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:212)
at com.sun.faces.context.ExternalContextImpl.getResponseOutputWriter(ExternalContextImpl.java:847)
at javax.faces.context.ExternalContextWrapper.getResponseOutputWriter(ExternalContextWrapper.java:785)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.createResponseWriter(FaceletViewHandlingStrategy.java:1192)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:403)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.primefaces.rio.filter.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:32)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
这是我的ManagedBean代码
public void downloadFile() throws IOException {
FacesContext context = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) context.getExternalContext().getResponse();
try {
String path = FacesContext.getCurrentInstance().getExternalContext().getRealPath("/Report_Audit.jrxml");
JasperReport jasperReport = JasperCompileManager.compileReport(path);
Map<String, Object> parameters = new HashMap<String, Object>();
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, parameters, new JREmptyDataSource());
byte[] pdfBytes = JasperExportManager.exportReportToPdf(jasperPrint);
response.setContentType("application/pdf");
response.setHeader("Content-Disposition", "attachment;filename=Auditoria.pdf");
response.getOutputStream().write(pdfBytes);
response.getOutputStream().flush();
response.getOutputStream().close();
response.flushBuffer();
} catch (JRException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
}
这是调用方法的按钮：
<span style="float: right;">
<p:commandButton id="btnPDF" icon="fa fa-file-pdf-o Fs16 White" styleClass="Fright RedButton" action="#{auditView.downloadFile}" ajax="false" />
<p:tooltip for="btnPDF" id="toolBtnPDF" value="Generar PDF"/>
</span>
提前致谢。我希望你们能帮助我。