Question

在Skillkill上进行软件演示之后，我在Eclipse中构建了一个简单的Spring MVC Demo应用程序。该应用程序加载正常，我可以访问主页（“ Hello World”）。但是，当我尝试按下控制器时，会收到以下错误消息

HTTP状态404-找不到

类型状态报告

消息 /springMVCDemo/WEB-INF/jsp/quote.jsp

描述：原始服务器找不到目标资源的当前表示，或者不愿意透露其存在。

我研究了以下描述相同错误的链接，但是我无法使我的代码正常工作

Tomcat 404 error: The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists. on deploying to tomcat

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

web.xml

<web-app>
    <display-name>Archetype Created Web Application</display-name> 
    <servlet>
    <servlet-name>MyDemoApp</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/myDemoApp-servletConfig.xml</param-value>
    </init-param>
    </servlet>

    <servlet-mapping>
    <servlet-name>MyDemoApp</servlet-name>
    <url-pattern>*.html</url-pattern>
    </servlet-mapping>
</web-app>

myDemoApp-servletConfig.xml

<?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:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

<mvc:annotation-driven/>
<context:component-scan base-package="com.demo.controllers"</context:component-scan>
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/jsp/"/>
    <property name="suffix" value=".jsp"/>
</bean>
</beans>

MyDemoController.java

package com.demo.controllers;

import java.util.Random;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class MyDemoController {
private String[] quotes = {"To be or not to be -Shakespeare",
                            "Stay hungry you're alone -Dee Snider",
                            "Might as well jump! -David Lee Roth"};

//http://localhost:8080/springMVCDemo/getQuote.html
@RequestMapping(value="/getQuote")
public String getRandomQuote(Model model) {
    int rand = new Random().nextInt(quotes.length);
    String randomQuote = quotes[rand];

    model.addAttribute("randomQuote", randomQuote);
    return "quote";
}

}

Quote.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>My Demo App</title>
</head>
<body>

<h1>The quote is:</h1>
<p>${randomQuote}</p>

</body>
</html>

index.jsp

<html>
<body>
<h2>Hello World!</h2>
</body>
</html>

目录结构

springMVCDemo
|
-->main
   -->java
      -->com
         -->demo
            -->controllers
               -->MyDemoController.java
-->webapp
   -->WEB-INF
      myDemoApp-servletConfig.xml
      web.xml
      index.jsp
      -->jsp
         -->Quote.jsp

我尝试过的内容和结果

实验1：

http://localhost:8080/springMVCDemo

结果：浏览器显示“ Hello World！”。符合预期

实验2：

http://localhost:8080/springMVCDemo/getQuote.html

预期的行为：显示三个引号之一

实际结果：HTTP 404 + Eclipse控制台消息：

Dec 29, 2018 5:59:40 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'MyDemoApp'
Dec 29, 2018 5:59:40 PM org.springframework.web.servlet.DispatcherServlet initServletBean
INFO: FrameworkServlet 'MyDemoApp': initialization started
Dec 29, 2018 5:59:40 PM org.springframework.web.context.support.XmlWebApplicationContext prepareRefresh
INFO: Refreshing WebApplicationContext for namespace 'MyDemoApp-servlet': startup date [Sat Dec 29 17:59:40 EST 2018]; root of context hierarchy
Dec 29, 2018 5:59:40 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from ServletContext resource [/WEB-INF/myDemoApp-servletConfig.xml]
Dec 29, 2018 5:59:42 PM org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping registerHandlerMethod
INFO: Mapped "{[/getQuote],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public java.lang.String com.demo.controllers.MyDemoController.getRandomQuote(org.springframework.ui.Model)
Dec 29, 2018 5:59:42 PM org.springframework.web.servlet.DispatcherServlet initServletBean
INFO: FrameworkServlet 'MyDemoApp': initialization completed in 1751 ms

实验3：

http://localhost:8080/springMVCDemo/getQuote2.html

结果：正如这里预期的那样，由于没有这样的映射，我得到了HTTP 404。还显示了以下Eclipse控制台消息：

Dec 29, 2018 6:03:21 PM org.springframework.web.servlet.PageNotFound noHandlerFound
WARNING: No mapping found for HTTP request with URI [/springMVCDemo/getQuote2.html] in DispatcherServlet with name 'MyDemoApp'

总而言之，我相信我的控制器已正确映射，但是由于某些原因，该页面无法显示：（

我正在使用的软件版本

Eclipse 2018-09（4.9.0）; Tomcat v9.0

如果任何人都可以提供一些故障排除建议，将不胜感激。我花了将近8个小时来尝试定制servlet配置文件，但到目前为止还没有运气。

Answer 1

我注意到您的代码中有几件事：

您的控制器的映射是getQuote，它似乎是根据服务器的以下日志配置并运行的：

INFO：映射 “ {[ / getQuote ]，方法= []，params = []，标题= []，consumes = []，produces = []，custom = []}” 到公共java.lang.String上 com.demo.controllers.MyDemoController.getRandomQuote（org.springframework.ui.Model）

您的jsp名称是Quote，而不是quote（区分大小写）：

-> jsp -> Quote.jsp

因此，在getQuote的情况下，首先应向映射的URL发出请求：

http://localhost:8080/springMVCDemo/getQuote

在控制器中放置一个断点，并通过请求此URL检查您是否真的可以到达它。

还修复了Controller的返回页面，因为您的页面名为Quote，所以您返回的是报价页面（请注意区分大小写）：

@RequestMapping(value="/getQuote")
public String getRandomQuote(Model model) {
    ...
    return "quote";
}

如何对HTTP 404进行故障排除原始服务器找不到目标资源的当前表示形式

1 个答案: