http status 500-error实例化servlet类org.springframework.web.servlet.DispatcherServlet

Question

以上是我的程序的目录层次结构

我是初学者并学习MVC概念我编写了一个程序，它将输入（名称）放入文本框并打印Hello ...＆＃39; name＆＃39;。以下是我的目录结构和我创建的各种文件。

的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <display-name>MVC_HelloWorld</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file> 
  </welcome-file-list>

  <!-- default configuration -->
  <servlet>
   <servlet-name>HelloWorld</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  </servlet>



<servlet-mapping>
    <servlet-name>hello</servlet-name>
    <url-pattern>*.ap</url-pattern> <!-- this same extension should bbe used in form action -->
  </servlet-mapping>
</web-app>

的HelloWorld-servlet.xml中

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN"
"http://www.springframework.org/dtd/spring-beans-2.0.dtd">

<beans>
<!-- default handler mapping -->
<!--  file should be created under web inf annd it's view resolver file -->

  <!-- handler(Not rqd in case of default handler) -->
  <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />

  <!-- controller configuration -->
<bean name="/HelloWorld.ap" class="controller.HelloController"> <!-- mapping url pattern to controller class using 'name' -->

<!-- view resolver -->

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
       <property name="prefix" vlaue="/"/> <!-- default location (prefix used foor rqd page locations) -->
       |<property name="sufix" value=".jsp"/> <!-- sufix used forr rqd page extensions -->

</bean>

</bean>

</beans>

HelloController.java

package controller;

import java.util.HashMap;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

import com.sun.javafx.collections.MappingChange.Map;

public class HelloController implements Controller {

    @Override
    public ModelAndView handleRequest(HttpServletRequest req, HttpServletResponse res) throws Exception {

        String name=req.getParameter("name");

        Map m= new HashMap();   // creating output object
           m.put("msg","Hello..."+name);

          ModelAndView mav=new ModelAndView("success"+m);



        return mav;
    }

}

的index.jsp

<h1> Hello World</h1>

<form action="./hello.ap">

NAME: <input type="text" name="name">
      <input type="Submit" value="Say Hello">
</form>

的success.jsp

${msg}

当我运行此代码时，index.jsp页面在进一步执行时正常运行它显示错误500.代码有什么问题.. ??我在apache 8.5中使用Eclipse氧气

Answer 1

您在web.xml中的配置是错误的。

您正尝试将调度servlet映射为控制器 在Spring mvc中，与其他mvc框架（struts等）一样，有一个主要的servlet用于调度所有请求。

org.springframework.web.servlet.DispatcherServlet通常被命名为“dispatcher”，应该映射到顶级网址，通常是“\”

e.g。

  <servlet>
                <servlet-name>dispatcher</servlet-name>
                <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
                <init-param>
                    <param-name>contextConfigLocation</param-name>
                    <param-value>/WEB-INF/spring/dispatcher-servlet.xml</param-value>
                </init-param>
                <load-on-startup>1</load-on-startup>
            </servlet>
  ...  
    <servlet-mapping>
                <servlet-name>dispatcher</servlet-name>
                <url-pattern>/</url-pattern>
            </servlet-mapping>

控制器映射在此URL下，例如的HelloWorld

@Controller
@RequestMapping("/HelloWorld");"
public class HelloController implements Controller {}

由于您的初始项目远非经典的vanilla启动Spring MVC项目，看起来您使用的是非常古老的Spring版本（或Spring教程）。我建议从一些在线教程开始。

E.g。

http://www.journaldev.com/2433/spring-mvc-tutorial
http://www.mkyong.com/spring-mvc/gradle-spring-mvc-web-project-example/

Answer 2

尝试以下编辑到web.xml。

<servlet-mapping>
<servlet-name>HelloWorld</servlet-name>
<url-pattern>*.ap</url-pattern> <!-- this same extension should bbe used in form action -->
</servlet-mapping>