Spring的@RequestBody在POST上提供空字符串

也许您在拦截器中某个地方或在web.xml中定义的过滤器中调用getParameter.另一个选择是，例如，如果您的控制器有一些其他带有复杂@RequestMapping的方法(例如读取参数值或标头值)，则Spring会为您执行此操作.我为您提供两个建议: 添加一个servlet过滤器(在spring有机会采取行动之前)，并使用您自己的包装器包装请求(只需扩展 HttpServletRequestWrapper ).这样，您可以在请求对象的某些方法上放置断点或记录消息，并查看谁在调用它们. 使用pojo对象参数，并设置绑定.看来是一种更简洁的读取帖子数据的方法. I have an application with Spring 3.0.5.RELEASE trying to get the full content of a post using @RequestBody. The method is called, but the string passed is always empty. I have checked, by placing breakpoints, that the StringHttpMessageConverter is called, but the inner HttpInputMessage is empty.I've seen this issue with both Jetty and Tomcat, so I'm discarding it's a problem with the container.Here is my sample controller:@Controller@RequestMapping("/")public class SubscriptionController { @RequestMapping(value = "/requestbody", method = RequestMethod.POST) public ModelAndView mycustomAction(@RequestBody String body) { // body is always empty Logger.getLogger(this.getClass()).debug("REQUEST BODY '" + body + "'"); return new ModelAndView("empty"); }}My application context is defined as follows:<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">  <context:component-scan base-package="com.big.viajerotelcel.controller" />  <mvc:annotation-driven />  <bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource"> <property name="basenames" value="classpath:i18n/messages" /> <property name="defaultEncoding" value="UTF-8" /> </bean>  <mvc:interceptors> <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor" p:paramName="locale" /> </mvc:interceptors>  <bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver" />  <bean id="tilesConfigurer" class="org.springframework.web.servlet.view.tiles2.TilesConfigurer"> <property name="definitions"> <list> <value>/WEB-INF/general.xml</value> </list> </property> </bean>  <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView" /> </bean>  <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">  <property name="maxUploadSize" value="5120000" /> </bean> </beans>I'm testing this using curl as follows:Any ideas or help is more than welcomed! 解决方案 Here is a code snippet of ServletServerHttpRequest, which extends HttpInputMessage. I am pretty positive this is the implementation that you are using in your code:public InputStream getBody() throws IOException { return this.servletRequest.getInputStream();}In other words, the request body is meant to be read as the input stream of the HttpServletRequest object.The request's input stream is not valid in several situations, but I can't find the correct documentation for it at the moment. For example, if you call request.getParameter() on a post request, tomcat has to read the input stream in order to interpret the parameters, thus afterwards when you read the input stream, it is empty because it has reached the end already.Perhaps you are invoking getParameter somewhere in an interceptor or perhaps a filter defined in web.xml. Another option is that Spring is doing that for you, for example, if your controller has some other method with complex @RequestMappings (such as reading param values, or header values).I have two suggestions for you:Add a servlet filter (before spring gets a chance to act), and wrap the request with your own wrapper (just extend HttpServletRequestWrapper). This way you can put breakpoints or log messages at some methods of the request object and see who's calling them.Use a pojo object parameter, and setup the bindings. It seems like a much cleaner way to read post data. 这篇关于Spring的@RequestBody在POST上提供空字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！