我收到一个异常：java.lang.IllegalStateException: 已经为此响应调用了 getOutputStream()
I am getting an exception: java.lang.IllegalStateException: getOutputStream() has already been called for this response
我想编写代码来下载一个保存在我系统中的文件
这是我的代码：
在控制器中class我有以下映射
@RequestMapping(value = "/processFile", method = RequestMethod.POST)
public @ResponseBody ModelAndView downloadFileProcess(
@RequestParam("file") File originalFile,
@RequestParam("action") String action, HttpServletResponse response) {
ModelAndView model = new ModelAndView();
model.setViewName("error");
System.out.println("");
System.out.println("Action: "+action);
model.addObject("message", "Action:" + action);
try {
utility.downloadFile(originalFile, response);
message = "The file was downloaded successfully";
} catch (IOException e) {
e.printStackTrace();
message = "The process failed due to following reason: "
+ e.getMessage();
} catch (Exception e) {
e.printStackTrace();
message = "The process failed due to following reason: "
+ e.getMessage();
}
model.setViewName("success");
model.addObject("message", message);
return model;
}
实用程序class中的方法如下：
public void downloadFile(File originalFile, HttpServletResponse response)
throws FileNotFoundException, IOException {
response.setHeader("Content-Disposition", "attachment; filename="
+ originalFile.getName());
IOUtils.copy(
new FileInputStream(new File(String.valueOf(originalFile))),
response.getOutputStream());
response.flushBuffer();
}
因为我要下载文件，所以我必须使用response.getoutputstream()。
但我收到以下异常：
java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed
at org.apache.catalina.connector.ResponseFacade.sendRedirect(ResponseFacade.java:482)
at org.springframework.web.servlet.view.RedirectView.sendRedirect(RedirectView.java:548)
at org.springframework.web.servlet.view.RedirectView.renderMergedOutputModel(RedirectView.java:279)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:267)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1221)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1005)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:952)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
2015-05-31 12:42:07.547 ERROR 15009 --- [nio-8080-exec-4] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet dispatcherServlet threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:678)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:213)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:104)
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:187)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1221)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1005)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:952)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:748)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:604)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:543)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:342)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:434)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:205)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$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)
2015-05-31 12:42:07.551 ERROR 15009 --- [nio-8080-exec-4] o.a.c.c.C.[Tomcat].[localhost] : Exception Processing ErrorPage[errorCode=0, location=/error]
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:748)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:604)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:543)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:342)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:434)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:205)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
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)
Caused by: java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:678)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:213)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:104)
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:187)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1221)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1005)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:952)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
... 27 common frames omitted
您希望单个请求有两个不同的响应：
- 一个包含下载文件的字节作为其正文
- 其中包含由成功视图生成的 HTML 页面
这没有道理。它只能是其中之一。如果您希望请求下载文件，那么您不应该 return ModelAndView。该方法应该 return 无效。
此外，该方法不应使用 @ResponseBody 注释。
AFAIK，下载站点同时生成成功页面和文件下载的方式简单地包括响应包含 iframe 的 HTML 页面，并将 iframe 指向 URL 用于实际文件下载。
这是 PrintWriter.getWriter() 和 HttpServletResponse.getOutputStream() 的问题，它们都试图将数据刷新到客户端。
您已经在使用 response.getOutputStream() 和 response.flushBuffer()，这意味着您正在尝试将内容刷新到客户端，最后当您的 downloadFileProcess() 返回时，Springs 也在尝试使用 PrintWriter.getWriter() 刷新内容所以你得到
java.lang.IllegalStateException: getOutputStream() has already been
called for this response
使用下面的代码向客户端发送一些内容，而不会使您的方法无效，这应该会有所帮助。
String content = null;
IOUtils.copy(new FileInputStream(new File(String.valueOf(originalFile))), content );
PrintWriter out = response.getWriter();
out.println(content);
附带说明一下，您为什么要在开始时执行 model.setViewName("error"); 和 model.addObject("message", "Action:" + action);？我认为要么你不应该拥有它，因为你最终会压倒一切，要么它们更适合 CATCH 块。
HttpServletResponse.getOutputStream()
- 用于向客户端写入二进制数据。
- 写入客户端的数据未编码。
- 调用 flush() 后，数据将刷新到客户端。
IllegalStateException 如果已在此响应对象上调用 getWriter() 方法，将抛出。
HttpServletResponse.getWriter()
- Returns 一个 PrintWriter 对象，可用于将字符文本（非二进制）数据写入客户端。
- 发送到客户端的数据使用默认编码方案或用户提供的编码。
- 调用 flush() 后，数据将刷新到客户端。
IllegalStateException 如果已经为此响应对象调用了 getOutputStream() 方法，将抛出
两者之间的一个关键用法差异是 getOutputStream() 用于向客户端发送二进制数据，而 getWriter() 用于发送编码文本数据。
底线： 上面两种方法中的任何一种都应该用于将数据刷新到客户端，而不是同时使用，开发人员必须确保它被正确处理，特别是在非 servlet 中做事时 class。
我这样解决了问题：
ApplicationContext context = new FileSystemXmlApplicationContext();
Resource resource = context.getResource("file:" + exFile.getPath());
File file = new File(exFile.getPath());
try {
response.setHeader("Content-Disposition", "attachment; filename=" + file.getName());
InputStream is = resource.getInputStream();
IOUtils.copy(is, response.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}
我想编写代码来下载一个保存在我系统中的文件
这是我的代码：
在控制器中class我有以下映射
@RequestMapping(value = "/processFile", method = RequestMethod.POST)
public @ResponseBody ModelAndView downloadFileProcess(
@RequestParam("file") File originalFile,
@RequestParam("action") String action, HttpServletResponse response) {
ModelAndView model = new ModelAndView();
model.setViewName("error");
System.out.println("");
System.out.println("Action: "+action);
model.addObject("message", "Action:" + action);
try {
utility.downloadFile(originalFile, response);
message = "The file was downloaded successfully";
} catch (IOException e) {
e.printStackTrace();
message = "The process failed due to following reason: "
+ e.getMessage();
} catch (Exception e) {
e.printStackTrace();
message = "The process failed due to following reason: "
+ e.getMessage();
}
model.setViewName("success");
model.addObject("message", message);
return model;
}
实用程序class中的方法如下：
public void downloadFile(File originalFile, HttpServletResponse response)
throws FileNotFoundException, IOException {
response.setHeader("Content-Disposition", "attachment; filename="
+ originalFile.getName());
IOUtils.copy(
new FileInputStream(new File(String.valueOf(originalFile))),
response.getOutputStream());
response.flushBuffer();
}
因为我要下载文件，所以我必须使用response.getoutputstream()。
但我收到以下异常：
java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed
at org.apache.catalina.connector.ResponseFacade.sendRedirect(ResponseFacade.java:482)
at org.springframework.web.servlet.view.RedirectView.sendRedirect(RedirectView.java:548)
at org.springframework.web.servlet.view.RedirectView.renderMergedOutputModel(RedirectView.java:279)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:267)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1221)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1005)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:952)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
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)
2015-05-31 12:42:07.547 ERROR 15009 --- [nio-8080-exec-4] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet dispatcherServlet threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:678)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:213)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:104)
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:187)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1221)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1005)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:952)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:748)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:604)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:543)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:342)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:434)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:205)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
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)
2015-05-31 12:42:07.551 ERROR 15009 --- [nio-8080-exec-4] o.a.c.c.C.[Tomcat].[localhost] : Exception Processing ErrorPage[errorCode=0, location=/error]
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:748)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:604)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:543)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:467)
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:342)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:434)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:205)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:678)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:213)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:104)
at org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$SpelView.render(ErrorMvcAutoConfiguration.java:187)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1221)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1005)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:952)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
... 27 common frames omitted
您希望单个请求有两个不同的响应：
- 一个包含下载文件的字节作为其正文
- 其中包含由成功视图生成的 HTML 页面
这没有道理。它只能是其中之一。如果您希望请求下载文件，那么您不应该 return ModelAndView。该方法应该 return 无效。
此外，该方法不应使用 @ResponseBody 注释。
AFAIK，下载站点同时生成成功页面和文件下载的方式简单地包括响应包含 iframe 的 HTML 页面，并将 iframe 指向 URL 用于实际文件下载。
这是 PrintWriter.getWriter() 和 HttpServletResponse.getOutputStream() 的问题，它们都试图将数据刷新到客户端。
您已经在使用 response.getOutputStream() 和 response.flushBuffer()，这意味着您正在尝试将内容刷新到客户端，最后当您的 downloadFileProcess() 返回时，Springs 也在尝试使用 PrintWriter.getWriter() 刷新内容所以你得到
java.lang.IllegalStateException: getOutputStream() has already been called for this response
使用下面的代码向客户端发送一些内容，而不会使您的方法无效，这应该会有所帮助。
String content = null;
IOUtils.copy(new FileInputStream(new File(String.valueOf(originalFile))), content );
PrintWriter out = response.getWriter();
out.println(content);
附带说明一下，您为什么要在开始时执行 model.setViewName("error"); 和 model.addObject("message", "Action:" + action);？我认为要么你不应该拥有它，因为你最终会压倒一切，要么它们更适合 CATCH 块。
HttpServletResponse.getOutputStream()
- 用于向客户端写入二进制数据。
- 写入客户端的数据未编码。
- 调用 flush() 后，数据将刷新到客户端。
IllegalStateException如果已在此响应对象上调用 getWriter() 方法，将抛出。
HttpServletResponse.getWriter()
- Returns 一个 PrintWriter 对象，可用于将字符文本（非二进制）数据写入客户端。
- 发送到客户端的数据使用默认编码方案或用户提供的编码。
- 调用 flush() 后，数据将刷新到客户端。
IllegalStateException如果已经为此响应对象调用了 getOutputStream() 方法，将抛出
两者之间的一个关键用法差异是 getOutputStream() 用于向客户端发送二进制数据，而 getWriter() 用于发送编码文本数据。
底线： 上面两种方法中的任何一种都应该用于将数据刷新到客户端，而不是同时使用，开发人员必须确保它被正确处理，特别是在非 servlet 中做事时 class。
我这样解决了问题：
ApplicationContext context = new FileSystemXmlApplicationContext();
Resource resource = context.getResource("file:" + exFile.getPath());
File file = new File(exFile.getPath());
try {
response.setHeader("Content-Disposition", "attachment; filename=" + file.getName());
InputStream is = resource.getInputStream();
IOUtils.copy(is, response.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}