点击导出按钮，它应该下载一个csv，其中包含从控制器形成的内容。 下面的代码下载了空的csv文件，没有任何数据，也引发了以下错误。
SearchPersonController.java：
@RequestMapping(value = "/export", method = RequestMethod.POST)
public @ResponseBody ModelAndView export( HttpServletRequest request, HttpServletResponse response ) {
try {
ServletOutputStream out = response.getOutputStream();
File file = new File("yourfile.csv");
FileWriter writer = new FileWriter(file);
writer.append("DisplayName");
writer.append(',');
writer.append("Age");
writer.append('\n');
writer.flush(); writer.close();
response.setContentType("csv");
response.setHeader("Content-disposition", "attachment; filename=" + file);
response.getOutputStream().flush();
response.getOutputStream().close();
}
catch (IOException e) {
throw new RuntimeException("IOError writing file to output stream");
}
return new ModelAndView("SearchPerson");
}
HTML：
<script>
$(document).ready(function() {
exportActionURL = function(obj) {
$("#searchPersonForm").attr("action", obj);
}
}
</script>
错误：
2015-08-03 11:26:04.941 INFO 4808 --- [nio-8080-exec-5] : export begin
2015-08-03 11:26:04.977 INFO 4808 --- [nio-8080-exec-5] : export end
2015-08-03 11:26:05.010 ERROR 4808 --- [nio-8080-exec-5] o.a.c.c.C.[.[.[.[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [/proj] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: getOutputStream() has already been called for this response] with root cause
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:578)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:212)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:109)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:109)
at org.springframework.security.web.context.SaveContextOnUpdateOrErrorResponseWrapper.getWriter(SaveContextOnUpdateOrErrorResponseWrapper.java:125)
at org.thymeleaf.spring4.view.ThymeleafView.renderFragment(ThymeleafView.java:335)
at org.thymeleaf.spring4.view.ThymeleafView.render(ThymeleafView.java:190)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1244)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1027)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$ApplicationContextHeaderFilter.doFilterInternal(EndpointWebMvcAutoConfiguration.java:291)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
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:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:105)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:57)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:102)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.boot.actuate.autoconfigure.MetricFilterAutoConfiguration$MetricsFilter.doFilterInternal(MetricFilterAutoConfiguration.java:90)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
我尝试更改代码如下：
@RequestMapping(value = "/export", method = RequestMethod.POST)
public @ResponseBody void export( HttpServletRequest request, HttpServletResponse response ) {
try {
ServletOutputStream out = response.getOutputStream();
File file = new File("yourfile.csv");
FileWriter writer = new FileWriter(file);
writer.append("DisplayName");
writer.append(',');
writer.append("Age");
writer.append('\n');
writer.flush(); writer.close();
response.setContentType("csv");
response.setHeader("Content-disposition", "attachment; filename=" + file);
response.getOutputStream().flush();
response.getOutputStream().close();
}
catch (IOException e) {
throw new RuntimeException("IOError writing file to output stream");
}
//return new ModelAndView("SearchPerson");
}
现在它没有抛出错误，但仍然没有填充数据。
答案 0 :(得分：0)
你正在调用getOutPutStream（）三次，这里
ServletOutputStream out = response.getOutputStream（）; response.getOutputStream（）平齐（）; response.getOutputStream（）close（）方法。 它应该像
out.flush();
out.close();