带有 java.lang.ClassNotFoundException 的 HTTP 状态 500：org.springframework.web.servlet.DispatcherServlet

Question

检查其他帖子没有帮助。 这是 Spring Tool Suite 版本：3.6.0。当我启动服务器时，网页打开。在我输入一个单词并点击提交后，我得到一个状态 500 错误。

Screen shot JARS

Directory Screen shot

Hellocontroller.java

  package controller;

import java.util.HashMap;
import java.util.Map;

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

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

//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();
           m.put("msg", "Hello ...."+name);                             

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

        return mav;
    }

}

HelloWorld-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context" xmlns="http://www.springframework.org/schema/beans"
    xsi:schemaLocation="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.xsd">

    <bean
        class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />


    <bean name="/hello.ds" class="controller.Hellocontroller">
    </bean>

    <bean class="org.springframework.web.servlet.InternalViewResolver">
        <property name="prefix" value="/" />
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>HelloWorld</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>*.ds</url-pattern>
    </servlet-mapping>
</web-app>

index.jsp

<h1>HelloWorld</h1>

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

NAME:<input type = "text" name="name">

SUBMIT<input type = "submit" value="sayHello">


</form

成功.jsp

${msg}

HTTP 状态 500 - 实例化 servlet 类 org.springframework.web.servlet.DispatcherServlet 时出错

---

type Exception report

message Error instantiating servlet class org.springframework.web.servlet.DispatcherServlet

description The server encountered an internal error that prevented it from fulfilling this request.

exception 

javax.servlet.ServletException: Error instantiating servlet class org.springframework.web.servlet.DispatcherServlet
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    java.lang.Thread.run(Unknown Source)


root cause 

java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve

Answer 1

尝试将 web.xml 更改为如下所示...在启动时添加负载

    <servlet>
        <servlet-name>HelloWorld</servlet-name>
         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  
        <load-on-startup>1</load-on-startup>  
    </servlet>

    <servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>*.ds</url-pattern>
    </servlet-mapping>