How to fix thrown IllegalStateException while getting report from web page

Question

I'm trying to get reports from web page. Actually report is generated as expected and it can be downloaded properly. But I get IllegalStateException in console, while debugging. Stack trace refers one of my method called "AddResponseHeaderFilter.doFilter()". The method only sets charset UTF-8 and the class implements javax.servlet.Filter.

Technology I used: Bussiness logic: Java(Spring), Report Engine: JasperReports, Application Server: Tomcat9

@Override 
public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        chain.doFilter(request, response);
    }

Stack Trace

java.lang.IllegalStateException: getOutputStream() has already been called for this response
    at org.apache.catalina.connector.Response.getWriter(Response.java:582) ~[catalina.jar:9.0.20]
    at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:227) ~[catalina.jar:9.0.20]
    at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:114) ~[servlet-api.jar:4.0.FR]
    at org.springframework.boot.web.servlet.support.ErrorPageFilter$ErrorWrapperResponse.getWriter(ErrorPageFilter.java:374) ~[spring-boot-2.2.0.M2.jar:2.2.0.M2]
    at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:360) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) ~[thymeleaf-spring5-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1370) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1116) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1055) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[servlet-api.jar:na]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.2.0.M1.jar:5.2.0.M1]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[servlet-api.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:9.0.20]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-websocket.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:9.0.20]
    at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:9.0.20]
    at com.beybo.filters.AddResponseHeaderFilter.doFilter(AddResponseHeaderFilter.java:33) ~[classes/:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:9.0.20]
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:130) ~[spring-boot-2.2.0.M2.jar:2.2.0.M2]
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:66) ~[spring-boot-2.2.0.M2.jar:2.2.0.M2]
    at org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:105) ~[spring-boot-2.2.0.M2.jar:2.2.0.M2]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:123) ~[spring-boot-2.2.0.M2.jar:2.2.0.M2]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:9.0.20]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.2.0.M1.jar:5.2.0.M1]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.2.0.M1.jar:5.2.0.M1]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[catalina.jar:9.0.20]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[catalina.jar:9.0.20]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[catalina.jar:9.0.20]
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678) ~[catalina.jar:9.0.20]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[catalina.jar:9.0.20]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[catalina.jar:9.0.20]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) ~[tomcat-coyote.jar:9.0.20]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-coyote.jar:9.0.20]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:836) ~[tomcat-coyote.jar:9.0.20]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1839) ~[tomcat-coyote.jar:9.0.20]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-coyote.jar:9.0.20]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-util.jar:9.0.20]
    at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

Code

@Controller 
@RequestMapping("/report") 
public class RaporController { 

    @GetMapping() String reporting(Model model, HttpServletResponse response) throws IOException { 
        JasperPrint jasperPrint = reportService.report(new Date(), sqlTable, false); 
        response.setContentType("application/pdf");
        response.setHeader("Content-Disposition", String.format("attachment; filename=\"" + reportService.getFilename() + "\""));
        OutputStream out = response.getOutputStream();
        JasperExportManager.exportReportToPdfStream(jasperPrint, out);
        return "home"; 
     }
}

@Controller @RequestMapping("/report") public class RaporController { @GetMapping() String reporting(Model model, HttpServletResponse response) throws IOException { JasperPrint jasperPrint = reportService.report(new Date(), sqlTable, false); response.setContentType("application/pdf"); response.setHeader("Content-Disposition", String.format("attachment; filename=\"" + reportService.getFilename() + "\"")); OutputStream out = response.getOutputStream(); JasperExportManager.exportReportToPdfStream(jasperPrint, out); return "home"; }} — a.akkus, Jun 13 '19 at 07:10

score 1 · Accepted Answer · edited Jun 13 '19 at 08:31

You are mixing the download of the PDF and the rendering of Thymeleaf.

Instead you should return a ResponseEntity with a byte[] that contains the PDF:

@Controller 
@RequestMapping("/report") 
public class RaporController { 

    @GetMapping() 
    public ResponseEntity reporting(Model model, HttpServletResponse response) throws IOException { 
        JasperPrint jasperPrint = reportService.report(new Date(), sqlTable, false); 
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        JasperExportManager.exportReportToPdfStream(jasperPrint, out);

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_PDF);
        headers.setContentDispositionFormData(reportService.getFilename(), reportService.getFilename());
        headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");

        return new ResponseEntity(out.toByteArray(), headers, HttpStatus.OK);
     }
}

Thank you for your fast and felicitous reply. – a.akkus Jun 13 '19 at 08:06 — a.akkus, Jun 13 '19 at 08:06
I'm always happy to help :-) – Simon Martinelli Jun 13 '19 at 08:09 — Simon Martinelli, Jun 13 '19 at 08:09

How to fix thrown IllegalStateException while getting report from web page

1 Answers1