Spring 4 异常处理：没有合适的参数解析器答案

【问题标题】：Spring 4 Exception Handling : No suitable resolver for argumentSpring 4 异常处理：没有合适的参数解析器
【发布时间】：2019-05-16 07:45:03
【问题描述】：

问题陈述

从Spring 3 迁移到Spring 4 会在异常处理流程中引发一些异常。 Exception 在org.springframework.web.method.support.InvocableHandlerMethod 类中显示No suitable resolver for argument。

所以每当发生异常时Spring 试图找到它得到的异常处理程序但是当它尝试填充方法参数或异常处理程序时，它会抛出以下异常

调用@ExceptionHandler方法失败：

  public org.springframework.web.servlet.ModelAndView  
       HelloController.handleCustomException(CustomGenericException, javax.servlet.http.HttpServletRequest, org.springframework.web.servlet.ModelAndView)

  java.lang.IllegalStateException: 
     No suitable resolver for argument [2] 
             [type=org.springframework.web.servlet.ModelAndView]

HandlerMethod详情：

Controller [HelloController]
Method [public org.springframework.web.servlet.ModelAndView  
        HelloController.handleCustomException(CustomGenericException,
            javax.servlet.http.HttpServletRequest,org.springframework.web.servlet.ModelAndView)]
        at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(
                     InvocableHandlerMethod.java:169)

它基本上是为@CRequestParam("p") String p变量而来的

代码

控制器

@RequestMapping(method = RequestMethod.GET, value="/exception2")
    public String getException1(ModelMap model, @CRequestParam("p") String p) {

        System.out.println("Exception 2 "+ p);
        throw new CustomGenericException("1","2");
    }

异常处理

@ExceptionHandler(CustomGenericException.class)
    public ModelAndView handleCustomException(CustomGenericException ex, 
            HttpServletRequest request, @CRequestParam("p") String p) {

            ModelAndView model = new ModelAndView("error/generic_error");
            model.addObject("exception", ex);
            System.out.println("CustomGenericException  ");
            return model;
    }

注释

@Target( { ElementType.PARAMETER })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CRequestParam {
    String value() default "";
}

参数解析器

public class CRequestparamResolver implements HandlerMethodArgumentResolver {


    @Override
        public boolean supportsParameter(MethodParameter methodParameter) {
          CRequestParam requestParamAnnotation = 
          methodParameter.getParameterAnnotation(CRequestParam.class);
        if(requestParamAnnotation==null){
        return false;
        }
        return true;
        }

    @Override
    public Object resolveArgument(MethodParameter methodParameter,
        ModelAndViewContainer mavContainer, NativeWebRequest webRequest,
        WebDataBinderFactory binderFactory) throws Exception {

    CRequestParam requestParamAnnotation = methodParameter .getParameterAnnotation(CRequestParam.class);

    if (requestParamAnnotation != null) {
        String requestParamName = requestParamAnnotation.value();
        if (StringUtils.hasText(requestParamName)) {
        return webRequest.getParameter(requestParamName);
        }
    }
    return null;
  }

XML 配置

<bean
        class="com.mkyong.common.resolver.AnnotationMethodHandlerAdapterConfigurer"
        init-method="init">
        <property name="customArgumentResolvers">
            <list>
                <bean class="com.mkyong.common.resolver.CRequestparamResolver" />
            </list>
        </property>
    </bean>

    <bean 
 class="org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver">
        <property name="customArgumentResolvers">
            <list>
                <bean class="com.mkyong.common.resolver.CRequestparamResolver" />
            </list>
        </property>
    </bean>

源代码

https://github.com/santoshjoshi/SpringMVC4

【问题讨论】：

我认为你的意思不是@CRequestParam，而是@RequestParam
@geo 及其自定义请求参数CRequestParam，我们有CRequestparamResolver 解析器。
@geo 并且整个源代码现已在https://github.com/santoshjoshi/SpringMVC4签入
你能发布一个更完整的堆栈跟踪吗？
AFAIK RequestMappingHandlerAdapter 不处理异常，因此无法使用它的参数解析器。看看ExceptionHandlerExceptionResolver.setArgumentResolvers()。我自己从未使用过它，但它看起来很有希望。

标签： java spring spring-mvc spring-4

【解决方案1】：

通过在请求本身中传递自定义参数解决了问题。

代码如下：

控制器

@RequestMapping(method = RequestMethod.GET, value = "/exception2")
public String getException1(ModelMap model, @CRequestParam("p") String p, HttpServletRequest request) {

  System.out.println("Exception 2 " + p);
  request.setAttribute("p", p);
  throw new CustomGenericException("1", "2");
}

异常处理程序

@ExceptionHandler(CustomGenericException.class)
public ModelAndView handleCustomException(CustomGenericException ex, HttpServletRequest request) {

  ModelAndView model2 = new ModelAndView("error/generic_error");
  model2.addObject("exception", ex);
  System.out.println(request.getAttribute("p"));
  System.out.println("CustomGenericException  ");
  return model2;

}

完整的源代码可在git获得

【讨论】：

【解决方案2】：

通过提供WebApplicationInitializer的实现解决了这个问题

public class SpringDispatcherConfig implements WebApplicationInitializer {

@Override
public void onStartup(ServletContext servletContext) throws ServletException {
    AnnotationConfigWebApplicationContext Contianer =   new AnnotationConfigWebApplicationContext();
    Contianer.register(SpringConfig.class);
    Contianer.setServletContext(servletContext);
    DispatcherServlet dispatcherServlet = new DispatcherServlet(Contianer);
    dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
    Dynamic servlet = servletContext.addServlet("spring",dispatcherServlet);
    servlet.addMapping("/");
    servlet.setLoadOnStartup(1);

}

【讨论】：