Question

@Override
    public void postHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {       

}

@Controller
public ModeAndView createUser(User user){



}

如何获取控制器方法createUser的参数用户值在拦截者的帖子中？

Answer 1

你不能直接。

正如您在参数中看到的那样，Interceptor可以直接访问请求，响应和ModelAndView。如果您需要访问方法参数user，最简单的方法是将其放入模型中。

public ModeAndView createUser(User user){
    ModelAndView mav = new ModelAndView();
    mav.addAttribute("user", user);
    ...
    return mav;
}

然后在拦截器postHandle方法中，你只需要

User user = (User) modelAndView.getAttribute("user");

Answer 2

你可以写一个org.springframework.web.servlet.HandlerInterceptor。（或其便利子类HandlerInterceptorAdapter）

@See：Spring Reference chapter: 15.4.1 Intercepting requests - the HandlerInterceptor interface

它有方法：

void postHandle(HttpServletRequest request,
                HttpServletResponse response,
                Object handler,
                ModelAndView modelAndView) throws Exception;

在控制器完成之后和渲染视图之前调用此方法。所以你可以使用它来为ModelMap添加一些属性

示例：

public class VersionAddingHandlerInterceptor extends HandlerInterceptorAdapter {

    /**
     * The name under which the version is added to the model map.
     */
    public static final String VERSION_MODEL_ATTRIBUTE_NAME =
                "VersionAddingHandlerInterceptor_version";

    /**        
     *  it is my personal implmentation 
     *  I wanted to demonstrate something usefull
     */
    private VersionService versionService;

    public VersionAddingHandlerInterceptor(final VersionService versionService) {
        this.versionService = versionService;
    }

    @Override
    public void postHandle(final HttpServletRequest request,
            final HttpServletResponse response, final Object handler,
            final ModelAndView modelAndView) throws Exception {

        if (modelAndView != null) {
            modelAndView.getModelMap().
                  addAttribute(VERSION_MODEL_ATTRIBUTE_NAME,
                               versionService.getVersion());
        }
    }
}

<强> webmvc-config.xml中

<mvc:interceptors>
    <bean class="demo.VersionAddingHandlerInterceptor" autowire="constructor" />
</mvc:interceptors>

如何在spring mvc的拦截器中访问postHandle中的控制器方法值

2 个答案: