Spring/Thymeleaf 抛出“提交响应后无法创建会话"；处理@PostMapping 时 [英] Spring/Thymeleaf throws "Cannot create a session after the response has been committed" when processing @PostMapping
问题描述
我使用 thymeleaf 视图构建了一个 Spring MVC 应用程序，但遇到了以下问题.我有一个页面，它应该处理一个表单并创建一个新的实体来保存在数据库中.在我的控制器类中，我有两种方法.首先，@GetMapping 来渲染页面:
I build a Spring MVC application with thymeleaf views and ran into the following problem. I have a page which should process a form and create a new Entity to persist in the database. In my controller class I have two methods for this. First, the @GetMapping to render the page:
@GetMapping("/dispo/orderCreate")
private String showCreateOrder(Model model) {
List<MdUser> userList = service.getUsers();
model.addAttribute("userList", userList);
return "/dispo/orderCreate";
}
就我只想显示页面而不向表单添加一些操作而言，一切正常.模型属性userList"已使用数据库中的用户正确填充.
As far as I just wanted to show the page without adding some action to the form, everything works fine. The model attribute "userList" is correctly populated with users from the database.
现在我更改了视图以向表单添加一个操作和一个对象.视图的代码现在看起来像这样:
Now I changed the view to add an action and an object to the form. The code of the view now looks like this:
<form action="#" class="form" id="newOrderForm" th:action="@{/dispo/addOrder}" th:object="${loadOrder}" method="post">
<table class="cont-table" cellpadding="2" cellspacing="2" width="100%">
<tbody>
<tr align="left">
<th align="left" valign="top" width="110">Protokollführer:</th>
<td>
<table border="0" cellpadding="0" cellspacing="1" width="100%">
<tbody>
<tr>
<td height="30">
<select class="selectOneMenue" id="newOrderPersoDropDown" th:field="*{supervisor}">
<option>Bitte auswählen</option>
<option th:each="user : ${userList}"
th:value="user.userId"
th:text="${user.firstName}+' '+${user.lastName}"></option>
</select>
</td>
. . .
</tr>
</tbody>
</table>
<br />
<input style="width:200px" type="submit" value="Speichern" class="commandExButton" id="newOrderSubmit" />
<input style="width:120px" type="reset" value="Zurücksetzen" class="commandExButton" id="newOrderReset" />
</form>
对应的@PostMapping如下所示:
The corresponding @PostMapping looks like this:
@PostMapping("/dispo/addOrder")
public String submit(@ModelAttribute("loadOrder") LoadOrderModel loadOrder, BindingResult result, Model model) {
if (result.hasErrors()) {
return "error";
}
service.createAndSaveLoadOrder(loadOrder);
return "/dispo/success";
}
现在，当使用以下堆栈跟踪到达表单时，视图的呈现会崩溃:
Now the rendering of the view crashes when the form is reached with the following stacktrace:
Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Error during execution of processor 'org.thymeleaf.spring5.processor.SpringActionTagProcessor' (template: "/dispo/orderCreate" - line 41, col 58)
at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:117) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.engine.TemplateHandlerAdapterMarkupHandler.handleOpenElementEnd(TemplateHandlerAdapterMarkupHandler.java:304) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler$InlineMarkupAdapterPreProcessorHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:278) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.standard.inline.OutputExpressionInlinePreProcessorHandler.handleOpenElementEnd(OutputExpressionInlinePreProcessorHandler.java:186) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:124) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.attoparser.HtmlElement.handleOpenElementEnd(HtmlElement.java:109) ~[attoparser-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.attoparser.HtmlMarkupHandler.handleOpenElementEnd(HtmlMarkupHandler.java:297) ~[attoparser-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.attoparser.MarkupEventProcessorHandler.handleOpenElementEnd(MarkupEventProcessorHandler.java:402) ~[attoparser-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.attoparser.ParsingElementMarkupUtil.parseOpenElement(ParsingElementMarkupUtil.java:159) ~[attoparser-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.attoparser.MarkupParser.parseBuffer(MarkupParser.java:710) ~[attoparser-2.0.4.RELEASE.jar:2.0.4.RELEASE]
at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:301) ~[attoparser-2.0.4.RELEASE.jar:2.0.4.RELEASE]
... 87 common frames omitted
Caused by: java.lang.IllegalStateException: Cannot create a session after the response has been committed
at org.apache.catalina.connector.Request.doGetSession(Request.java:3030) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.connector.Request.getSession(Request.java:2468) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:896) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:908) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:240) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:240) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.security.web.csrf.HttpSessionCsrfTokenRepository.saveToken(HttpSessionCsrfTokenRepository.java:63) ~[spring-security-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.security.web.csrf.LazyCsrfTokenRepository$SaveOnAccessCsrfToken.saveTokenIfNecessary(LazyCsrfTokenRepository.java:175) ~[spring-security-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.security.web.csrf.LazyCsrfTokenRepository$SaveOnAccessCsrfToken.getToken(LazyCsrfTokenRepository.java:127) ~[spring-security-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.security.web.servlet.support.csrf.CsrfRequestDataValueProcessor.getExtraHiddenFields(CsrfRequestDataValueProcessor.java:71) ~[spring-security-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.thymeleaf.spring5.context.webmvc.SpringWebMvcThymeleafRequestDataValueProcessor.getExtraHiddenFields(SpringWebMvcThymeleafRequestDataValueProcessor.java:80) ~[thymeleaf-spring5-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.spring5.requestdata.RequestDataValueProcessorUtils.getExtraHiddenFields(RequestDataValueProcessorUtils.java:79) ~[thymeleaf-spring5-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.spring5.processor.SpringActionTagProcessor.doProcess(SpringActionTagProcessor.java:118) ~[thymeleaf-spring5-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.standard.processor.AbstractStandardExpressionAttributeTagProcessor.doProcess(AbstractStandardExpressionAttributeTagProcessor.java:142) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) ~[thymeleaf-3.0.9.RELEASE.jar:3.0.9.RELEASE]
... 100 common frames omitted
由 TemplateProcessingException 指示的第 41 行是带有表单标记的行.我几乎没有前端开发经验，所以请耐心等待.我想我必须在这里做一些 http 会话管理，但不知道该怎么做以及如何做.有人可以帮我吗?
Line 41 as indicated by the TemplateProcessingException is the line with the form tag. I have nearly no experience with frontend development so please have patience with me. I think I have to do some http session managing here but don't know what to do and how to do it. Can anyone help me?
推荐答案
我终于做到了.问题确实出在 http 会话中，或者更准确地说，出在 HttpSecurity 中.所以我在 SecurityConfig 类的配置方法中添加了以下内容:
I finally made it. The problem indeed lied in the http session, or to be more precise, in the HttpSecurity. So I added the following to my configure method in my SecurityConfig class:
http.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.ALWAYS)
我仍然需要找出 SessionCreationPolicy.ALWAYS 对我的应用程序的其余部分意味着什么，但现在它可以工作:D.
I still have to find out what SessionCreationPolicy.ALWAYS means for the rest of my application but for now it works :D .
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