如何在 Spring MVC 中获取 HttpServletRequest？答案

【问题标题】：How do I get the HttpServletRequest in Spring MVC?如何在 Spring MVC 中获取 HttpServletRequest？
【发布时间】：2021-08-17 19:01:43
【问题描述】：

如何在 Spring MVC 中获取 HttpServletRequest？

在尝试获取 HttpServletRequest 时，我得到了一个异常。

留言 No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.

请告诉我如何解决这个问题？

    @Component
    public class AuthenticationSuccessEventListener implements ApplicationListener<AuthenticationSuccessEvent> {


        @Autowired
        private HttpServletRequest request;


        @Override
        public void onApplicationEvent(AuthenticationSuccessEvent a) {
            
            System.out.println(request.getRemoteAddr());
            
        }

    }

【问题讨论】：

标签： java spring spring-mvc spring-security

【解决方案1】：

您不应该在您的方面自动装配 HttpServletRequest，因为这样将您的方面绑定为仅可用于被调用的类从正在执行的 HttpServletRequest 中。

而是在需要时使用 RequestContextHolder 来获取请求一个。
private String getRemoteAddress() {
    RequestAttributes attribs = RequestContextHolder.getRequestAttributes();
    if (attribs instanceof NativeWebRequest) {
        HttpServletRequest request = (HttpServletRequest) ((NativeWebRequest) attribs).getNativeRequest();
        return request.getRemoteAddr();
    }
    return null;
}

https://stackoverflow.com/a/24029989/11985558

【讨论】：

【解决方案2】：

你可以试试这个

RequestAttributes reqAtt = RequestContextHolder.getRequestAttributes();
if (RequestContextHolder.getRequestAttributes() != null) {
    HttpServletRequest req = ((ServletRequestAttributes) reqAtt).getRequest();
    return req.getRemoteAddr();
}

你还需要在 web.xml 文件中添加/注册一个 RequestContextListener 监听器。

<web-app ...>
   <listener>
    <listener-class>
        org.springframework.web.context.request.RequestContextListener
    </listener-class>
   </listener>
</web-app>

【讨论】：