完整教程：Grails(Groovy)框架抛出NoHandlerFoundException而不是返回404 Not Found

本文记录在基于Spring(Boot)框架（使用Java语言）和Grails框架（使用Groovy语言）下，开发Controller接口，对不存在的URL请求，接口返回404 not found，而不是抛出NoHandlerFoundException异常的问题，以及排查过程。

对于Spring (Boot)框架，请参考Spring 。

本文带着对Grails的极大恶意，谨慎下翻。

Grails

对于Grails框架，使用Groovy开发的Controller接口，Postman请求不存在的index1接口，给出如下响应信息：
在这里插入图片描述
切换到Preview：
在这里插入图片描述
经过分析，Postman上看到的preview页面实际上是下图中的notFound.gsp文件：
在这里插入图片描述
notFound.gsp文件如下：

<!doctype html>
  <html>
    <head>
    <title>Page Not Found</title>
        <meta name="layout" content="main">
        <
          g:if env="development"><
      asset:stylesheet src="errors.css"/></g:if>
    </head>
    <body>
        <ul class="errors">
      <li>Error: Page Not Found (404)</li>
      <li>Path: ${request.forwardURI}</li>
      </ul>
    </body>
  </html>

gsp文件就是Grails下的JSP页面，实际上是XML文件。

console打印日志：WARN [nio-8895-exec-5] o.s.web.servlet.PageNotFound : No mapping for GET /index1
在这里插入图片描述
找不到这个类？？

NoHandlerFoundException

添加配置：

spring:
mvc:
throw-exception-if-no-handler-found: true
web: # 必须关闭静态资源的默认处理，否则 /health1 可能被静态资源处理器拦截或跳过
resources:
add-mappings: false # 谨慎使用，可能影响静态资源

报错：
在这里插入图片描述
Postman看到的还是上面的第二个图。

添加配置类：

package com.abcd
@Configuration
@EnableWebMvc
class NoHandlerConfig
{
@Bean
ServletRegistrationBean<DispatcherServlet>
  dispatcherServlet() {
  DispatcherServlet dispatcher = new DispatcherServlet()
  dispatcher.setThrowExceptionIfNoHandlerFound(true) // 关键设置
  ServletRegistrationBean<DispatcherServlet> registration = new ServletRegistrationBean<
    >
    (dispatcher, "/")
    registration.setName("dispatcherServlet")
    return registration
    }
    }

结果应用启动报错：

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.springframework.boot.actuate.autoconfigure.endpoint.web.CorsEndpointProperties' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}

注释404映射：
在这里插入图片描述
在这里插入图片描述
还是不行。

WTF？？

一个很简单的技术需求，在Grails框架体系下实现起来怎么这么困难？？？

原理

Grails使用自己的UrlMappings路由系统，它基于AbstractController和动态调度。当访问/health1：

  • Spring MVC层确实找不到Handler；
  • 但Grails的NotFoundController或默认的grails.web.mapping.filter.UrlMappingFilter拦截请求；
  • 最终返回404，根本不经过Spring的DispatcherServlet抛异常逻辑；
  • 所以：NoHandlerFoundException根本不会被抛出，无论你怎么配置throwExceptionIfNoHandlerFound。

经过各种折腾，终于有了一个将就的解决方法：
在UrlMappings.groovy最后面添加如下配置：

"/*"(controller: 'notFound', action: 'handle')

再人工实现一个NotFoundController：

class NotFoundController
{
def handle() {
throw new org.springframework.web.servlet.NoHandlerFoundException(
request.method,
request.forwardURI,
new HttpHeaders()
)
}
}

日志打印：

o.g.web.errors.GrailsExceptionResolver   : NoHandlerFoundException occurred when processing request: [GET] /health1
No handler found for GET /health1. Stacktrace follows:
java.lang.reflect.InvocationTargetException: null
Caused by: org.springframework.web.servlet.NoHandlerFoundException: No handler found for GET /health1

Postman渲染HTML错误信息：
在这里插入图片描述
上面代码里写的明明是new HttpHeaders()，这里却变成String？？？事实上，这个参数类型变更的问题，我后来又遇到过一次。

这特么太搞笑了。

GlobalExceptionHandler

想要实现的效果是，GlobalExceptionHandler.groovy实现全局Controller接口接管。对于404 Not Found，使用ERROR级别来打印日志（忽视下面截图里的错误，实际上应该是this.logError(e, "请求路径不存在")）：
在这里插入图片描述

UrlMappings.groovy

UrlMappings.groovy文件如下：

class UrlMappings
{
static mappings = {
"/$controller/$action?/$id?(.$format)?" {
constraints {
// apply constraints here
}
}
// 分组接口
group "/doc", {
"/"(controller: "document", method: "GET", action: "index") // 文档列表
"/$doc_id"(controller: "document", method: "GET", action: "detail") // 文档详情
}
// 单独接口
"/opts"(controller: "options", method: "GET", action: "index")
// 省略其他若干
"/"(view: "/index")
"500"(view: '/error')
"404"(view: '/notFound')
}
}

删除notFound.gsp文件（并没有注释UrlMappings文件里的404配置），请求/index1接口，报错：

javax.servlet.ServletException: Could not resolve view with name '/notFound' in servlet with name 'grailsDispatcherServlet'
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1385) ~[spring-webmvc-5.3.33.jar:5.3.33]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1150) ~[spring-webmvc-5.3.33.jar:5.3.33]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1089) ~[spring-webmvc-5.3.33.jar:5.3.33]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:965) ~[spring-webmvc-5.3.33.jar:5.3.33]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.33.jar:5.3.33]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.33.jar:5.3.33]
2024-12-31 14:00:57.501  --> ERROR [nio-8995-exec-4] o.a.c.c.C.[Tomcat].[localhost]           : Exception Processing ErrorPage[errorCode=404, location=/error]

PageNotFound

o.s.web.servlet.PageNotFound这个类到底是在哪个GAV里的？

这个类不存在，至少在spring-webmvc-5.x下面并不存在。

经过各种排查，

public class DispatcherServlet
extends FrameworkServlet {
public static final String PAGE_NOT_FOUND_LOG_CATEGORY = "org.springframework.web.servlet.PageNotFound";
protected static final Log pageNotFoundLogger = LogFactory.getLog(PAGE_NOT_FOUND_LOG_CATEGORY);
protected void noHandlerFound(HttpServletRequest request, HttpServletResponse response) throws Exception {
if (pageNotFoundLogger.isWarnEnabled()) {
pageNotFoundLogger.warn("No mapping for " + request.getMethod() + " " + getRequestUri(request));
}
if (this.throwExceptionIfNoHandlerFound) {
throw new NoHandlerFoundException(request.getMethod(), getRequestUri(request),
new ServletServerHttpRequest(request).getHeaders());
} else {
response.sendError(HttpServletResponse.SC_NOT_FOUND);
}
}
protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
mappedHandler = getHandler(processedRequest);
if (mappedHandler == null) {
noHandlerFound(processedRequest, response);
return;
}
}
@Nullable
protected HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
if (this.handlerMappings != null) {
for (HandlerMapping mapping : this.handlerMappings) {
HandlerExecutionChain handler = mapping.getHandler(request);
if (handler != null) {
return handler;
}
}
}
return null;
}
}

在这里插入图片描述
当Spring框架的DispatcherServlet无法找到处理请求的处理器（Handler）时，它会返回null，从而导致404 Not Found错误。

resources.groovy

resources.groovy文件如下：

import com.aliyun.oss.OSSClient
import io.minio.MinioAsyncClient
import io.minio.MinioClient
// Place your Spring DSL code here
beans = {
def grailsConfig = grailsApplication.config
ossClient(OSSClient, grailsConfig.oss?.endpoint, grailsConfig.oss?.accessKeyId, grailsConfig.oss?.accessKeySecret)
minioClient(MinioClient, MinioAsyncClient.builder()
.endpoint(grailsConfig.minio?.endpoint as String)
.credentials(grailsConfig.minio?.accessKey as String, grailsConfig.minio?.secretKey as String)
.build())
}

增加：

import org.springframework.web.servlet.DispatcherServlet
beans = {
dispatcherServlet(DispatcherServlet) {
throwExceptionIfNoHandlerFound = true
}
}

结果报错：
在这里插入图片描述
console控制台打印异常日志：

ERROR [nio-8867-exec-5] o.g.web.errors.GrailsExceptionResolver   : NullPointerException occurred when processing request: [GET] /temp/all
Stacktrace follows:
java.lang.NullPointerException: null
at org.grails.web.mime.HttpServletResponseExtension.getMimeTypeForRequest(HttpServletResponseExtension.groovy:131) ~[grails-plugin-mimetypes-6.2.1.jar:6.2.1]
at org.grails.web.mime.HttpServletResponseExtension.getMimeType(HttpServletResponseExtension.groovy:127) ~[grails-plugin-mimetypes-6.2.1.jar:6.2.1]
at org.grails.web.mime.DefaultMimeTypeResolver.resolveResponseMimeType(DefaultMimeTypeResolver.groovy:41) ~[grails-plugin-mimetypes-6.2.1.jar:6.2.1]
at org.grails.web.mapping.mvc.UrlMappingsHandlerMapping.findRequestedVersion(UrlMappingsHandlerMapping.groovy:184) ~[grails-web-url-mappings-6.2.1.jar:6.2.1]
at org.grails.web.mapping.mvc.UrlMappingsHandlerMapping.getHandlerInternal(UrlMappingsHandlerMapping.groovy:132) ~[grails-web-url-mappings-6.2.1.jar:6.2.1]
at org.springframework.web.servlet.handler.AbstractHandlerMapping.getHandler(AbstractHandlerMapping.java:499) ~[spring-webmvc-5.3.39.jar:5.3.39]
at org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1266) ~[spring-webmvc-5.3.39.jar:5.3.39]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1048) ~[spring-webmvc-5.3.39.jar:5.3.39]
ERROR [nio-8867-exec-5] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: class org.springframework.web.context.request.ServletRequestAttributes cannot be cast to class org.grails.web.servlet.mvc.GrailsWebRequest (org.springframework.web.context.request.ServletRequestAttributes and org.grails.web.servlet.mvc.GrailsWebRequest are in unnamed module of loader 'app')] with root cause
java.lang.ClassCastException: class org.springframework.web.context.request.ServletRequestAttributes cannot be cast to class org.grails.web.servlet.mvc.GrailsWebRequest (org.springframework.web.context.request.ServletRequestAttributes and org.grails.web.servlet.mvc.GrailsWebRequest are in unnamed module of loader 'app')
at org.grails.web.mapping.AbstractUrlMappingInfo.evaluateNameForValue(AbstractUrlMappingInfo.java:119) ~[grails-web-url-mappings-6.2.1.jar:6.2.1]
at org.grails.web.mapping.DefaultUrlMappingInfo.getNamespace(DefaultUrlMappingInfo.java:185) ~[grails-web-url-mappings-6.2.1.jar:6.2.1]
at org.grails.web.mapping.mvc.AbstractGrailsControllerUrlMappings.collectControllerMapping(AbstractGrailsControllerUrlMappings.groovy:206) ~[grails-web-url-mappings-6.2.1.jar:6.2.1]
at org.grails.web.mapping.mvc.AbstractGrailsControllerUrlMappings.matchStatusCode(AbstractGrailsControllerUrlMappings.groovy:120) ~[grails-web-url-mappings-6.2.1.jar:6.2.1]
WARN [nio-8867-exec-5] c.z.security.config.AdviceConfiguration  : [Web][有Warn被抛出] >> Warn类=[java.lang.IllegalArgumentException], URI=[/error], 消息=[不合法的参数异常], Warn=[java.lang.IllegalArgumentException: HandlerMapping requires a Grails web request
at org.springframework.util.Assert.notNull(Assert.java:201)
at org.grails.web.mapping.mvc.UrlMappingsHandlerMapping.getHandlerInternal(UrlMappingsHandlerMapping.groovy:130)

应用启动时，报错如上面的StackTrace所示，后续的接口请求，则报错StackTrace顶部的空指针：

ERROR [nio-8867-exec-9] c.z.security.config.AdviceConfiguration  : [Web][有异常被抛出] >> 异常类=[java.lang.NullPointerException], URI=[/temp/all], 消息=[null]

而且是所有的Controller接口都会报错NPE！！！！

NPE

臭名昭著的空指针！为啥会NPE？？
在这里插入图片描述
UrlMappingsHandlerMapping.groovy源码：

@CompileStatic
class UrlMappingsHandlerMapping
extends AbstractHandlerMapping {
protected String findRequestedVersion(GrailsWebRequest currentRequest) {
String version = currentRequest.getHeader(HttpHeaders.ACCEPT_VERSION)
if(!version && mimeTypeResolver) {
MimeType mimeType = mimeTypeResolver.resolveResponseMimeType(currentRequest)
version = mimeType.version
}
return version
}
}

DefaultMimeTypeResolver.groovy源码：

@CompileStatic
class DefaultMimeTypeResolver
implements MimeTypeResolver {
@Override
MimeType resolveResponseMimeType(GrailsWebRequest webRequest= GrailsWebRequest.lookup()) {
if (webRequest != null) {
return HttpServletResponseExtension.getMimeType(webRequest.response)
}
return null
}
}

HttpServletResponseExtension.groovy源码：

@CompileStatic
class HttpServletResponseExtension
{
@CompileStatic
static MimeType getMimeType(HttpServletResponse response) {
final webRequest = GrailsWebRequest.lookup()
return getMimeTypeForRequest(webRequest)
}
private static MimeType getMimeTypeForRequest(GrailsWebRequest webRequest) {
HttpServletRequest request = webRequest.getCurrentRequest()
MimeType result = (MimeType) request.getAttribute(GrailsApplicationAttributes.RESPONSE_MIME_TYPE)
if (!result) {
// 省略代码
}
return result
}
}

WTF？webRequest是null的？？

其他

网络上有很多对Grails的吐槽

posted @ 2025-07-25 12:50  yjbjingcha  阅读(30)  评论(0)    收藏  举报